In order of preference:
4081 Best for draw, flavor, and durability. Their problem is that the the auto batts suck, the carts are small and no one ever made a
black mouthpiece. Still my favorite atty on a 3.7
mod.
401 Nice vape, draw, flavor, the best with the auto batt, closest size/feel to an analog. good on a 3.7
mod. Carts are small but they wick dry. Don't waste
juice.
901 Good for vapor and flavor but they just don't last, don't wick well and they leak all over.
510 Great vapor, no flavor... except that nasty taste you get after 2 good draws. They leak, and the carts don't wick.
801, no advantages that justify the size. Leaks all over, carts hold lots of liquid but it never gets to the coil.
just my .02.