I'm using a PS3 controller and I've been wondering the same thing.
It has really bad lag input (a few 100ms). I'm not sure what can fix it. Although there was 1 revision of dolphin that had no lag input for the ps3 controller. Not sure which 1 it was though.
It has really bad lag input (a few 100ms). I'm not sure what can fix it. Although there was 1 revision of dolphin that had no lag input for the ps3 controller. Not sure which 1 it was though.