I've had 6 discs now for about 3 months or so. They've been pretty good in general. I had issues with all the discs associating with the master only, and not daisy chaining leaving me with a couple of poor connections; a couple of google homes disconnesting constantly; the master disc randomly going off line, and either coming back on its own, or I'd have to hard reboot the master disc.
With the latest firmware installed, I have to say that all my issues seem to have been resolved. I can't really confirm whether the google home issue is sorted yet as only got one of the Homes back online yesterday (my fault).
Before the BT WHWifi, I bought and tried the Google Wifi product. I couldn't get it to talk to my BT Smart Hub router, and couldn't get the slaves to link to the master. Ended up getting a refund. Also, I have BTTV and have had issues using non-BT powerlines adaptors in the past, so I tend to stick to BT products now. I do have a netgear switch connected via ethernet to one of the slaves, and that seems to work perfectly too, supplying the BT TV box.
I do have the wifi on my router disabled.
A colleague has the Linksys Velop product, and he seems pleased with that. Has it linked to a virgin router.
When they're working they are great products. I just think that the massive variability in the networks and items that have to connect to them means that there will always be issues with some installations.
...until tonight when it has just all gone off for no reason. Master Disc reboot has got it back up and running again but topology has no daisy chaining. Grrrrr.......
If you purchase from Amazon - you'll have a good amount of time to try it out and send back without hassle.