Same. Exclusively top here. My experience is, if you care how your bottom feels with your every stroke (for that reason I always fuck missionary), you can see from your bottom's eyes the exact moment he's getting (real) close.
Sudden acceleration of that rubbing motion on his prostate (from your cock, of course) will make him shaking with his orgasm...
I enjoy too much the scene of my bottom in nirvana to cum first.
That said, I wouldn't last too long with that supercharged fucking either.