my personal opinion....
i am 110% bottom, and small dicks hurt, whereas a large dick doesnt.......doesnt make sense, but its true......a longer thicker dick (to me) hits all the right places, where a small dick feels like im being jabbed to death......
I suspect tops don't care as much about dick size, as it is their dick that will get more use... versatile guys have it all.
As a bottom though, I agree big dicks buried in my bum are the best.