I’ve struggled for complete Wi-Fi coverage over many years and many devices, this product appears to have completely resolved every dissatisfaction I’ve had with all other Wi-Fi AP products. I’ve only had it set up for a month, but so far it has been the most positive home networking experience I’ve had. Supper easy to set up, range is amazing…blows away all the other home/consumer networking products I’ve tried.
I used three of the UniFi AP-LR devices. Configured one with a wired connection out and the other two as wireless links to that one. All power is set to high at this point, I’ll tinker with that some in the future. I also configured 3 networks over the set: household (secured), dev (secured) and guest (secured voucher based). So far all TVs, home automation, PCs, Laptops, Tablets, and Phones work well.
Three of the LR (long range) units with power settings to high is certainly overkill, so you may want to consider starting with one unit for the average home usage.
I can even let people visiting my home pay for there daily Wi-Fi voucher via my PayPal account…just like a hotel! 
http://www.ubnt.com/unifi