OK... I think I've had it with Z-Wave. I've been a Z-Wave user since the original generation. At the time, it was the most reliable solution and way more robust than X10 (yes I used to own several of those POS dimmers). However, I've come to find out that nothing, and I mean nothing, beats WiFi. As long as you have a good WiFi system, it is FAR, FAR, FAR, FAR...(did I say FAR?) superior. It's faster, more reliable and I never have to worry about it. Right now, I'm using Kasa switches and dimmers (really sucks that there isn't a OOTB 3-way dimmer though). I just can't for the life of me figure out why my Z-Wave devices annoyingly decide to take WAY longer paths than necessary, or randomly drop off line. I had it working great with my Vera system and have since switched to Hubitat. Hubitat is a fantastic solution which I prefer but I just can't do this with Z-Wave anymore. It makes no sense. As long as you can stay local and not use the cloud with WiFi, I see no reason to use Z-Wave. My use case is a 5200 square foot home with 4 Ubiquiti Unifi NanoHD's, a Unifi AC-HD and a Unifi AC-M. I also have (for God knows what reason) foil backed drywall on my ceiling (I'm in Ohio and it isn't necessary but that's how they built my house). My Kasa devices are rock solid, as are my homebrew ESP32 devices and my Leviton dimmers (I know the Leviton devices use the cloud which is a downside). I can't reliably get Z-Wave devices to work even with repeaters (which the devices choose not to use for some reason anyway). Z-Wave sucks. Many of my Z-Wave devices are prior to Plus. But I don't think that is the reason. Maybe it is. Somebody please convince me otherwise. Sorry for the rant. Talk me off the ledge.
Here's an older post from another thread.. Note: I'm not implying that you are unfamiliar with the differences just that I wanted to credit @marktheknife with the posting..
Less than half the bandwidth and shorter range.. And polling..
Best thing I ever did was get rid of all pre-plus devices..
I get that many of the pre-plus devices (Jasco Dimmers) need replaced but I'm debating now as to why replace them with more Z-Wave devices rather than something WiFi. If you can setup a good network I don't get the reasoning for choose something with a "non-standard" security and less bandwidth. Full Discloser... I am a certified and independent AMX/Crestron/Extron programmer. I'm definitely not new to home automation though 95% of my customers are commercial clients. I'm used to dealing with Lutron/Leviton/Crestron lighting. For my house though, I've tried just about everything as an experiment from time to time. I've pretty much had everything from an AMX Radia system to Crestron CLX modules. I like the idea of controlled dimmers in the box. It makes more sense. I'm just thinking that WiFi is a far superior medium. If only they made a Z-Wave over IP protocol I think I'd have the best of all worlds.
They did.. No one is using it for devices.. Technically we support it if they ever come out with devices.. All the 700 series SDK is IP based..
BTW my entire home is Z-Wave.. No Zigbee or WiFi..
Lutron? (Runs away before he gets kicked) 
Local control...As for security, AES128 and 256 have been around a long time... Also the saturation for wifi bandwidth is horrible and I have no desire to rely on other people's servers. The fact that you have older z-wave devices that aren't as good as z-wave plus goes to show that technology advances. I'm not going to sit here and try to convince you to stay with z-wave or zigbee or any other protocol. That has been talked to death everywhere. I've been a network engineer for 37 years. I understand IP very well and it's weakness'. For HA? No thank you.
You are conflating Local/Cloud control with WiFi. Wifi doesn't mean cloud control. I can disconnect my internet right now and all of my WiFi devices will continue to work perfectly fine.
Also, I'm not sure where you live but for me personally WiFi saturation isn't an issue. I continuously get near wired speeds anywhere on my property ( 1.25 acres). If I can stream 4K video, I'm pretty sure I can pass a packet to turn on a light switch reliably.
I am not a huge fan of Z-Wave either. I decided to rip all of the Z-wave out of my house and I replaced it all, and then some, with a complete Lutron lighting system. Best home automation decision I have ever made. 100% solid, stable, and reliable. Very fast all local LAN integration with Hubitat. For sensors, I use Zigbee motion, contact, and leak sensors, with Zigbee smart outlets spread throughout the house to help create a strong mesh network. I will not be going back to Z-wave...ever! 
Yeah, reliability needs to be 99% or it is basically useless in my opinion. I understand that some people can get a proper Z-Wave mesh network installed but I've never had a problem with WiFi. Perhaps some people have problems with WiFi which I can understand. If that is the case, then maybe they are more comfortable with Z-Wave. Regarding Zigbee... No thank you on that either. I used to have 10-12 AMX R4 Zigbee remotes. My God that was a PITA. I struggled through firmware updates forever with those. It was a beautiful remote but just didn't get reliable until maybe the 4th year of release. And being 2.4Ghz when that reigned supreme in WiFi didn't help. I'd always map frequencies out but still had problems at certain times of the day (damn neighbors).
I had some issues with z wave non plus, after replacing them all went better, still have some non plus devices in a separate z wave network which includes my front door lock, but I also tested kasa, no thank you.
I have 15 wifi devices in my network connected to Hubitat, not counting the 6 speakers, I hate them sometimes... but at the end, you decide what is better for you, so good luck with that and let us know what you did.
Well it depends which devices you're talking about. In smart home terms, a lot of them will continue carrying out their pre-set schedules since that is often stored on the device itself, but you often can't control them if you want them off or on outside their schedule, or to change their schedule, until the internet is connected again.
Most wifi stuff isn't local...and most people like myself don't live on an acre and a half. People live in neigborhoods with smaller lots, apartments, etc where wifi saturation is very high.
Warning: Rambling, barely-on-topic post ahead, but it got it out of MY head.
I don't care one way or another what you do, but I also argued that wifi switches were the way to go until I installed a few. I live on a 56 acre island with exactly four full time residents. The only other house (hundreds of yards away) has exactly one wifi router and a single wifi repeater device that I installed for them, and they have a total of four devices that use wifi there. So, wifi congestion is a complete non-issue for me.
Our property has three buildings and four Peplink enterprise-grade access points, so it's blanketed with great wifi coverage. I have about three wifi devices, in total. I'd say they're about 90-95% reliable, as I notice a missed command enough that I could tell you the last time it happened, within a day or two at any given time. In contrast, I have three Hubitat C-7s (one in each building), each running a Z-wave network. I think there are about 40 z-wave devices, in total. Two buildings each have two Aeotec repeaters. I honestly can't remember the last time I had a missed command, so I'll say it's 99.x% reliable.
So, for my "n of one" experiment, Z-wave with Hubitat has been dramatically better. YMMV, of course, as is always true.
To continue the saga, we just bought a small building in the nearby town for my wife to have a gallery/workspace/shop and be able to visit with other humans, which she seems to enjoy occassionally. Due to a lack of neutrals there, I went with Lutron Caseta (that muttering one might hear is me cursing the need for a "Pro" bridge to connect to Hubitat) for all but one light, which will get a Zigbee switch as it sits 8 feet from the HE, and the Lutrons won't work with the single LED lamp it controls. I'll report back sometime on how the Lutron-HE marriage works out. I've long liked Casetas in other properties we've had, and found them flawless except for the occasional LED incompatibility.
I'm trying to get there. Some obscure devices (e.g. Intermatic PE653 pool controller) are old Z-Wave so they have a semi-permanent place.
I'm not smart enough to know whether the problems I see are due to Z-Wave protocols or to my C-3 hub not knowing what it's doing. Multiple tickets to support and referrals to the Engineering black-hole have yielded no interest from Hubitat to analyze the problem.
OK...First off, that sounds AWESOME! Please let me know what days sound best for me to come visit! I'm wondering if my problems aren't related to the foil backed drywall on my ceilings. I'm basically living in a faraday cage. When I first moved in it took my damn near a year to get the WiFi designed and 100% reliable because of it. I'm going to need to dive in further. Like I said, at one point my Vera was solid. Now, I have to get it back again on hubitat. Just frustrated with the setup woes.
OMG
All of my lighting switches / dimmers ar Z-Wave plus. My network is solid and do not have any issues. My concern with wifi is not as much local vs cloud as it is the addition of the wifi access points between the HE and the device. I like the fact that HE talks directly to the Z-Wave network. Just my 2 cents.
After struggling with my Zwave network since moving over to hubitat from Smartthings (and, most likely, having many of the same issue on Smartthings but never realizing it...), I followed several pieces of advice found in this thread and others on this forum:
- Ditched all non-Plus devices. This solved several issues, while also gaining function from newer / modern devices.
- I identified 2 devices that were faulty / not routing traffic correctly. This only became apparent after removing the non-Plus devices / polling was off. I replaced those devices.
- Segmented my network. I have a 3 story house (2 main floors plus a basement) and had consistent issues with devices in my garage and basement areas (which are effectively concrete boxes...). Almost every light switch in the house is a Zwave Plus device, and even as mains repeaters, PLUS dedicated 700 series repeaters deployed throughout the house, it wasn't cutting it. I now run 3 hubs: one dedicated and located in my garage, one dedicated and located in my basement, and lastly one on the 2nd floor that runs devices on that floor and the 3rd / top floor. I then segmented devices in the garage and basement to those respective hubs, all connected via Hub Mesh, and localized automations appropriately.
After the above, my network is rock solid and everything is stable.
