It really depends on the dynamic with the other guy I range from cocky to total sub with some of my regular tops, and I enjoy it all.
I tend to be more 'sub' for guys older, more hung, and larger and physically stronger than me. If they can pin me down and hold me there, my ass is theirs to take pleasure in until they nut. And I don't even care if I get off or not.
I'm much more cocky with guys more my 'equal' if that makes sense. I make the calls on the positions and angles and am the one fucking him and his cock, not the other way around. Power bottoming can put a top right in your control. I love to have them on their back and ride them balancing on my thighs and slamming it home. You can have a top wimpering just as easily as a bottom.
It's funny though, I used to be mostly a top and would reluctantly bottom only on occasion, and I didn't really enjoy it. Then I had a bottoming epiphany and started to really get into it a couple years back. I'm glad though my versatility has given me perspective on how to be a better bottom though. Kegels really pay off, and my tight grip has my tops coming back for more.