with a 1.5-1.8 speed dagger in offhand chain drive is almost an instant proc(like GCD instant) during burn...
but, for highest burst dps, 2h hammer is preferred to the higher damage/dps, but post burn, 1h+dagger pulls ahead of 2h dps-wise. except 2h gets only 1 recon and no stat stick, so if you are looking for dps, unless u have a good tank, prepare to have to manage aggro very carefully, while 1h+dagger gets higher post-burn dps, a stat stick, and another recon. most tanks go 1h+dagger(2 hatreds also), while dps can go either, depending on playstyle, and i know some dps ch/r that even have both, and switch, depending on role, tank, dps needed etc...
rereading that, it's a dense paragraph, sorry lol