I've been a DD-WRT user for many years now. I have considered the other options before installing DD-WRT on the N66U (which I received just after Christmas), but none of them were offering significantly better functionalities over DD-WRT for what I needed, so I just went with what I knew worked well.

I have 2 routers running DD-WRT (RT-N66U as my main router and TP-WR1043ND as a wireless bridge) and it works like a charm.