Back when I was shopping, er, I guess a year ago, I was shopping the Orbi products from Netgear, almost pulled the trigger, then just wound up with a second Apple Airport Extreme (6th Gen) for downstairs as an AP. We have a cable modem and AE #1 (in router mode) and a Homerun HD, in the gear closet upstairs, with a couple of ethernet runs (ATV/AV is wired in the bedroom), including a drop down to the second floor to a switch on the AV rack (everything on the rack is ethernet), and the AE #2 connected to that switch (sitting up on the mantel), running in "bridge mode", so you can sort of roam around with coverage all over (including the deck and driveway and most of the yard). So the iOS devices are all on WiFi, so are the laptops, etc.
anyway ...
If I were buying today, I'd seriously look into the Nest product line from Google.