That's interesting. The largest apt I've lived in was a 850 sq ft 2br so I've never had any issue with the range or lag from my router. Thanks for sharing.
However, seeing better performance 5 GHz 802.11 n/ac requires you to have both a good router and a good laptop -- my experience is that unless your users/family blindly uses Macbooks, they won't see any improvement from a $200 router because their 2-3 year old $500 Windows laptop only has a 802.11 b/g/n 2.4 GHz-only 1x1.