Common advice is to go with 2-stage fermentation (especially for heavier worts) to avoid having the fermenting beer sit upon the trub. I've read other opinions, which say that there's no harm, and sometimes even added benefits, to have the fermentation take place on top of the spent yeast.
Basically, I would like to know the consensus about this. I have a 6.5 gal conical, so I've been able to get away with a "middle ground" approach (having much less surface area for trub to be in contact). What do you think is best practice?
(This might get filed with the controversial "don't sparge" movement, heh)