Finally bit the bullet and installed Tomato after issues with my ASUS RT-N16 re-booting and generally being crappy under heavy load transfering files wirelessly on the stock firmware.
I have installed three 8dBi TP-link antennas on my router and my desktop PC runs a TP link wireless N card, equipped with three TP-link 8dBi extension antennas that sit onto of my monitor.
The two are seperated by approx 12 meters and 4 interior walls.
Speeds are alot better between the router's gigabit connection and my desktop (tp-link wireless card). Currently sustaining 8.5-9 MB/s according to DuMeter.
The only issue I have is slow transfer speeds to a connected USB device (FAT formatted, not NTFS). Approx 4 MB/s. Is this an issue with the hardware that handles the asus's USB functions?
Otherwise, tomato is excellent. Currently sitting on 12 days uptime, very happy :)