Z-Wave seems to coexist with multiple radios (on with active devices or disabled) without any issues from what I've seen.
I've got four hubs running, one of them with many Z-Wave devices, one with one Z-Wave device, the other two not doing anything with Z-Wave. I haven't had any issues at all. Z-wave is pretty much perfect. 
Until it isn't.
I think that's pretty much true of everything. 
ZWave is a 'burst' transmission... we know this because battery devices would last days not months of it had to transmit all the time. Therefore, the 'higher power' portion of a ZWave radio (SOC) chip is quiescent anytime it's not actively transmitting. When ZWave is disabled on the hub, packets are prevented from reaching the SOC and thus it never has any transmitting to do. No interference possible if it's not transmitting.
I disagree. I am a C7 owner, and I've been patiently waiting for a C9 hub. The hub releases were:
C5: Feb 2019
C7: July 2020 (1yr 5mo after C5)
C8: March 2023 (2 yrs 8mo after C7)
C8-Pro: Jan 2024 (10 months after C8)
We are now 2yrs 4mo after the C8 Pro release. Who wants to risk spending $165 on a 2+ year old hub if a C9 is right around the corner? People with C5s and C7s have had them for years, I doubt they will jump ship when a new one could be so close. I will personally keep my C7 until it either breaks or a new hub is announced. Preferably one with better processing & RAM because I occasionally get warnings of max processing / memory.
And I'd prefer my Hubitat to do it all, including being the Thread router.
I really hope they release a new version in the next 6 months.
C-9 is not right around the corner. We’re still unlocking the full potential of the C-8 Pro, which remains one of the most competitive smart home automation hubs available today — built for speed, privacy, reliability, and complete local control.
There isn't. My reasoning:
Zwave 700 series chip came out in 2019
Zwave 800 series chip came out in 2022
Hubitat released a new hub in the following years.
The C8-Pro is way more than capable at the moment and for near future. Unless you seriously think they will release a C8 Pro Ultra, I wouldn't hold my breath.
Update: I see Bobby responded while my message was being drafted.
that follows my speculation also - the change in hub would likely follow a major Z-wave versioning since moving to internal radios; i.e. C-5 = Z-wave 500 ... so until / unless Z-wave series 900 I doubt the next hub (whenever that may be down the line) will be a C-9
who knows Silicon Labs may skip it to avoid confusion with 900 MHz ... hearing they may move away from 3-digit series and next could just be series 3 (not to be confused with Zigbee 3) and get this the new future may be Z-Wave IP - where the actual radio chip speaks IP natively (like Thread)... not to be confused with legacy Z/IP 
Maybe they will pull an Apple, skip 9 and the next hub will be X 
The hub is based on the z-wave chip. There isn't a z-wave 900 chip coming
I acknowledge there is no z-wave 900 chip announced, and Bobby's reply that there is no C-9 coming around the corner (likely for the exact reason of there not being a z-wave 900 chip announced, so any C-9 would likely be well over a year+ away).
However, the C-8 to C-8 Pro did not require a new z-wave chip. I don't see why we wouldn't have a "C-8 Ultra" or similar that gets improvements such as:
Item 3 might be possible with a future SW update to C-8 Pro, but the others would require a new hardware update.
I can't imagine the Hubitat team would be willing to go 3+ years without a new hardware release to increase sales.
Uh, @bobbyD has spoken. There is nothing to imagine. Do you need a notarized letter from Hubitat?
Since the release of the C8 Pro, Hubitat has been continuously adding functionality. Developers, super users, and power users have been pushing the hardware and accomplishing amazing things and the hub hardly breaks a sweat. Except for a very slow annoying memory loss in the last round or two of firmware, my C8P and most others continually have over 900MB of free memory just sitting around. Except for the rogue app, driver, device, or user stupidity (let me be the first to put myself in that line when repeatedly scanning 600+ devices to try out a handful of amazing recent community apps), the C8P barely uses a small fraction of the CPU it already has.
Would it be cool/neat to have those 5 items? Yes. Would I go out and buy a C8P Ultra because of it? No. #4 isn't really needed (see above) and #5 would add cost, space, redesign and unnecessary supply chain and inventory management, especially when there are so few needing such a feature and plenty of discussion here with 3rd party solutions for those who need it.
This will continue. The C-8 Pro has Thread-capable hardware; it would not surprise me if a future update permits use of the C-8 Pro as a TBR.
Would this be in addition to the zigbee and zwave, or is the hardware limitation such that the TBR would take over teh zigbee, leaving those of us with zigbee devices without a zigbee hub?
it can do zigbee and connect via WiFi instead of Ethernet so I am hoping it would take the place of the wifi
I have 2 C8Pros in production, 2 C8s, and one C7 occupying space in my closet.
I'm sure a quick note to @csteele to arrange a "change" to HPM could change Tray's mind... If not a few others....
Has anyone from the UK ordered a C8 Pro direct from the Hubitat web site recently?
It's now listed at £126. Vesternet are charging £200. I did email Vesternet to see if they would match the price and I got a firm NO.
Just wondering if import duty will be charged and how much.
The reason I'm posting here is this is the cheapest I've seen it and makes me wonder if a C9 IS actually on it's way. I know Booby D said otherwise earlier but it does make me think. (Never a good thing according to my wife!!)
Believe the Bobby. He does not prevaricate, is not a dissembler, won't beat around the bush, and certanly has no reason to say a firm no when he could just ignore this topic entirely.
C9 is not currently in the winds...
Yeah I got one about a month ago direct from Hubitat after seeing the price at Vesternet. There are no import duties - what you see is what you pay. Mine was delivered stupid fast from Scottsdale, Arizona to Middlesbrough, North Yorkshire. I was impressed to say the least.
Thanks for the reply. Time to upgrade..... 