I am also very curious on how well the band steering is working and what kind of setup/options there are for it. Does the firmware/admin console allow you to select specific device to move to specific channels? Or specific speed classes of devices? Or is it all black box other than setting seperate SSIDs for each 5GHz radio?
The thing that is starting to bother me is the lack of DFS channel usage on routers (and lesser degree some clients not supporting them). With 11ac and 80MHz channel widths, the non-DFS channels only allow two non-overlapping 80MHz networks (180MHz total, 4 20MHz channels in the low range, 5 20MHz channels in the upper range). If you added in DFS though, that would allow (assuming they are all open in your area, and likely most are) another 2 non-overlapping 80MHz networks (IIRC there is 180 or 190MHz of DFS in the US in the 5GHz range).
Just a single R8000 covers both non-overlapping ranges with nothing left over if you wanted to deploy another AP. Or, worse, when 160MHz wave 2 devices hit the market...without DFS a single one without even having seperate radios/bands different devices can connect on will gobble ALL of 5GHz unless DFS becomes a feature and NOT a rare option on routers.