Damn I am having issue with my RT-N66U. I was able to connect to the router and then I walk away (10 feet away from my router) and i lost connection. I had to re connect. This is on 5GHz. I havent try connecting to 2.4GHz.
My setup for 5GHz
Wireless Mode N Only
Channel 161
Channel bandwidth : 40 MHz
Extension Channel : Auto
WPA is AES
I have the same router and distance wise it didn't cut out but I do notice a drop in speed from the same distance as my iphone(30 feet or so) through two walls the nexus 5 was slower bringing in data by about 15-20%