I have a large home - with about 30 Z-wave devices.
They worked pretty well on my C7 - but I had some devices showing low bandwidth, occasionally not responding to commands, etc.
I just bought and migrated to the C8 with the hope of improving my Wave connectivity. I would first like to say - huge thanks for making the migration so seamless. It worked flawlessly.
here's what my topology looks like now - after the migration. I should have grabbed a screenshot before - but didn't think about it until after the migration.
now that the C8 has WiFi - I may choose to move it to a more central location in the house - but before I do that - should I do a Z-Wave Refresh or repair?
in case it matters - most of my devices are GE dimmer / switches - which were discovered and show up as "SPECIFIC_TYPE_POWER_SWITCH_MULTILEVEL Jasco Products"
the house is pretty large - and it's two levels. the majority of the switches are on the primary level - only a few are downstairs.
the c7 (and now c8) is currently located on the primary level, in the northeast corner of the house - it's the really the only location that had wired ethernet.
my wifi coverage is very good - so I can move the c8 anywhere that might help - but wanted to reach out to the group here to see what might be best to do.
thanks @staze - my config / coverage looks the "same" as it did on the c7. my primary reason to upgrade was to try to help my coverage - so just looking to the wisdom here to see how best to proceed. thanks!
I generally keep an eye on a couple things. First, the obvious one - do the devices work? Second, how many reroutes do they go through, third what does the hub show as RTT? And fourth, how many repeaters in the route. I learned recently that RTT is not valid for battery operated devices so I generally judge by how quickly lights come on after a z-wave motion sensor triggers, etc. The reroute number is really a pretty good indicator of how well a device is communicating. But that stat, along with several others, gets reset after a reboot, so you have to let it run for a while.
I had a solid mesh on the C7. Since the migration I have had some pretty significant z-wave issues with devices chewing through batteries, slow to respond, etc., and some with lots and lots of reroutes. It seems to happen in waves, as if something gets overloaded at various times. But so far I haven't been able to track down a root cause, other than of course the migration itself. Fortunately while my situation is not unique it is at least not all that common.
Looking at his ZWave Details, @marcsnyder doesn't have any battery devices.. they don't have a Repair button, and all of his devices show a Repair. I don't remember ever seeing a zero battery home before. I need to restart my DC Voltage Distribution System I designed a year or more ago to distribute 12VDC to individual buck converters within a USB cable distance of each of my battery devices. If it weren't for the 'climb around in the fiberglass filled attic' step, I'd be done.
The majority of his devices display a good count of neighbors, very few of his RTT/RSSI values are populated. His device labeled Great Room is concerning, because those values are poor, in my estimation, especially for a 100kbps connection.
100% as Brad says, @marcsnyder. If you don't have an obvious problem (devices not responding, responding w/noticeable lag, etc.) then I'd leave things as they are. You didn't say if the issues on the C7 ("...occasionally not responding to commands, etc.") are there on the C8 as well. Are you having those issues on the C8?
The other recommendation is if the migration is <3 days old I'd wait and let the Z-Wave mesh settle in. Then if you have devices that have issues you can try addressing those individually via individual Z-Wave Repair (Repair button on the Z-Wave Details page for that device) or even remove/re-pair them.
You can re-locate your hub using Wi-Fi, but I'm a big fan of Ethernet as it just always works and doesn't add another area that needs attention/concern when troubleshooting.
If it weren't for the 'climb around in the fiberglass filled attic' step, I'd be done. 
