I always thought I was on the small side of average, at least until I got out there and got to compare with more guys. I'm about fifteen (maybe fifteen and a half) centimeters when erect, although I'm more used to thinking of it as a hair over six inches. My partner - who's hung like a horse - says it's the perfect size and that he wouldn't want to bottom for somebody much bigger.
Personally, I would rather face an average to slightly over average size cock if I have to bottom - I've bottomed some, not all that often, and a few times I even really liked it, but I'm just more of a top.
Ericool85, I'd say yours is in the perfect size range. It's not so small or so large that it would hurt when you topped someone, at least in my opinion. Guys whose dicks are too long or too thick are painful, and guys whose dicks are way too small can't seem to keep it in the hole and have to keep stabbing it back in there. I know there are size queens out there, but so what? There are guys out there who only want movie-star looks, too - and they're usually shallow as hell.
I say, be proud of what you got, because nobody else has one quite like it.