From an absolute stand point, I believe i could likely pull more conventional than sumo, but I've never tried to pull those types of weights conventional. Getting too old to find out actually. Perhaps my best days of "ego weights" are behind me? If so, it's been a great ride.
But from a rep stand point, sumo pulls are much easier to bang out for extended sets (5+). At least for me.
All the best,
Lifting heavy stuff is fun and relative......