As an update to my initial post on page 454 with regards to my RT-N66U, I conclude that I get slightly better WiFi range with the E version compared to the L version. 4-5 mbps compared to 2-3 mbps across 4 floors worth of distance. I also noticed that I get a better signal quality if I position the low dBi antennas in an XYZ configuration, which surprised me because I thought focusing two of the antennas perpendicularly to the direction would yield a better result.