Just simply doing kegels won't really affect your size except MAYBE a little girth if your PC muscle is very unfit. REVERSE kegels when used in conjuction with the DLD Blasters are maybe the best length exercise though. Do a search for them.
I don't quite agree. Kegels probably won't affect gains at all but it sure can affect size if your PC muscle is unfit. If it is you aren't having the kind of erections you could have (hands up everyone who has gotten better erection quality from kegels) and then you're not at you fullest potential at any given moment.