Thanks Tony. And I agree on all your points.
Z-wave routing - while it works the majority of the time - is definitely more reliable in static installs where interference is minimal and highly static.
Variable interference and/or non-stationary devices can really throw it for a loop at times. Although sometimes when a device moves, explorer frames do their job and pick a decent route, but it is not a guarantee.
Tony and Jason,
Thank you very much for yours very educational messages.
But it is what is.
My repeater never was added into any route.
But its physical location somehow influence a network performance.
Now I am very confused - should I add more repeaters?
Also, all my troubles with ZWave network started immediately after
I switched from C-5 to C-7.
My C-5 ZWave network was in a good shape with majority of the
devices added to the C-5 hub (only few more added directly to the C-7).
So, 700 series is not quite backward compatible.
As a result I have extra C-7 hub and I had to store aside few Zooz toys.
I've also had some luck after installing a repeater by taking a problematic edge device, attempting to exclude it, doing a factory reset, and re-including it. In a couple of instances that has allowed it to discover a better path to the hub. And in other cases it has created more ghost devices, so I make sure I have my zwave stick on standby!
On the other hand... (perhaps this is the fifth hand 
)
There are plenty of examples of 'mobile devices' working just fine. I have a case from yesterday... One of my Aeon Recessed Door sensors had a dead battery. I pulled it and took it upstairs, opposite side of the house. The C-7 it talks to is 15 ft away normally, so it should have had a direct route. (which is good in this example.) I more or less had to walk past the C-7 on my way to my battery collection. Once I swapped the battery, the sensor responded instantly.. as in I put the battery in, slid the internals into its case and clicked the lid on. I then used my "spare" magnet to test it, and it works. I then took it downstairs, across the house and stuck it back in it's normal hole-in-the-wall. It worked perfectly, instantly.
I am attributing this wonderful behavior on the simple fact that at no time did the device need to alter the direct route. Admittedly, had I read this topic before changing the battery I would have verified that when it was upstairs getting it's new battery, it did not need a routing hop. In fact, it's got me very curious now. I think I'll test this out. I'll go to that sensor, remove it's battery, walk it upstairs, opposite side of the house and use Zniffer to see how it is in fact routing when the battery goes back in. The 'battery changing room' has several impediments to a good signal. There is a good chance that a device repair would cause it to pick a routed path. It might just be that, while the signal is marginal, it didn't have to change AND I wouldn't have seen any retries (delays) in my interpretation "instant".
Do you need an additional device to use ZNiffer? A ZWave probe of some sort? Or will the stick do it?
Zniffer does need a dedicated USB stick because it needs a dedicated image that replaces the factory image on the stick.
I think it's theoretically possible to revert the USB Stick back to factory (non-Zniffer) and I did make a backup of mine when it arrived. I have never tried to revert and for me, I don't think it's likely that I would. $35 is just not enough to justify the hassle of swapping the image.
The Zniffer software talks to the USB Stick and I have that on a VirtualBox VM, since it must be a Windows PC, and I don't own one. 
I just leave it plugged in all the time... right beside my 700 series ZWave USB stick that is used to remove ghosts. Both are powered 24x7.... not that you'd need to.. I'm just explaining that I have a tech nerd bias. 
Yeah I use VMWare Fusion and I upgraded from Win7 to Win10 to use the PC Controller software (not necessary at the end of the day). The only other thing I run on that VM is some software-defined-radio controller software so it sits there until I need it.
Just ordered my second Z-Stick.
As of today I don't have any Z-Stick(s) and all associated SW tools.
It is absolutely clear : Knowledge is a Power.
But say, if I will have (I don't mind to buy toys) all these HW and SW handy,
how this will help me to solve ZWave Mesh problem(s)?
I know which node(s) are problematic without any detailed knowledge about mesh.
So, will all these toys help me to solve a problem(s) or it will be just for education?
And if this is real solution for the problem which Z-Stick should I buy?
If a problem need more knowledge to achieve a solution, then these toys add to your knowledge potential. You might glean something in the "ahha" range, but more likely it will be "oh, so that's what they meant."
I think the most widely used purpose is to use PC Controller to remove ghost devices that won't go away any other way. I used the Silicon Labs stick but I believe others will work. The Ziffer app I assume gives you roughly the same functionality as a sniffer... though it has been years since I've used one myself.
Well,
I figured out how to remove ghosts (even unremovable with remove status : 0)
without Z-Stick (I already posted my algorithm in a different thread).
Anyway, I like toys so I am ready to buy one.
My preferable source is Amazon.
There are few available (mostly 500 but few 700).
So questions:
N1: 500 or 700 or even both?
N2: Is Aeotec good one (or something else)?
Well the uzb-7 is great and inexpensive.. and I've purchased 2 from Digi-Key with no issues. The Aeotec Z-Stick+ is nice even though it's only 500 series because it has a battery and you can walk around and exclude problematic devices. edit: you might also be able to INCLUDE (with no security) but I have not done this detached from a computer..
I use one UZB-7 for PC Controller stuff and the other is running on a test Home Assistant setup at the moment.
The Z-Stick+ I use for residential work when working with a lot of smart switches/devices that are spread out. Also use the UZB-7 as well.
Thank you for the advice on Z-Sticks.
Just ordered both from Amazon (Digikey is out of stock).
Aeotec ZW090 will be in on Saturday.
SiLab SLUSB001A will be in by July 13.
The SiLabs SLUSB001A is in stock at Mouser for $19.00.
I would not flash the Aeon to Zniffer because it would negate its true value, and that's the battery.
Wait to get the SiLab one and flash it to Zniffer. Then use the Aeon to tie into the PC Controller software. That one you'll join to each ZWave network you have.. on per hub. You can of course Exclude it from one Hub and then Include it to another... if you want to see how SmartThings is doing something, for example.
@csteele - Is there Zniffer firmware for the UZB-7? I have a UZB-3 that I flashed a while ago for that purpose. Sadly haven't zniffed in a while.. 
Thank you for the info.
Lead time is about 2 weeks, the same as Amazon.
Respectfully, you are mistaken. Admittedly, the Mouser product page is a little confusing; they had 361 in stock (now 360 after my order today). I just ordered another one (my first one was from DigiKey) and it’s shipping today to arrive in 2 days. I could have gotten it tomorrow if I wanted to pay expedited shipping.
That lead time is if you need more units than the number they have in stock (which as @672southmain indicated is currently 360).
What better choice for the Z Wave Repeaters?
I have one Aeontec 7 dedicated repeater plus bunch of switches with repeating capability.
No matter what I am trying the Aeontec 7 Repeater 9installed about 10 days ago) is not
used by any node(s). But I do need to improve my ZWave network.
I am thinking to buy few plugable outlets/dimmers with repeating capabilities.
Is this OK or I absolutely must buy dedicated repeaters?
Download the Hubitat app
