I've recently decided to switch to sumo stance DL's, after several months spinning my wheels alternating between sumo and conventional basically at random. Reasons are my build (short limbs) and that sumos don't beat up my back as badly. Best DL was 180kg back in October, at ~85kg (5'7).
I've been reading up on all things sumo dl related, and I've found some excellent resources:
Fantastic, wide ranging Mike Robertson article:
Marc Bartley on switching to sumo:
Interesting Elite Fitness roundtable: