yeah screw, if you stick to good form now it will pay off BIG TIME. I'm just now focusing on a controlled negative on all of my movements and my strength seems to be really going up.
I can only do 12 (with a 75lbs dumbell hanging from a belt) Body weight only I have done twenty, but could have done more. When I started doing them 8months ago, could only do five with my body weight.
If i am fresh maybe 10 if its a good day. My forearms always seem to be the first to go so my bi's never get a really good workout. Also for some reason after 2-3 reps i start rocking like crazy and usually have to drop my feet to the floor to stabilize which always screws me up.