Newbie has questions about a BL setup

So the radio shack gp 3300 is what i should try. Ill get a set of them and ill compare. Those batteries seemed to work allright but do i need to discharge them every once in a while cause they dont seem to have the punch they had when i first charged them. when i first got them they worked better than my 3000mah power max pros by peak racing. I got a set of them off tower hobbies, and there more expensive than the GPs from radio shack, but im not sure if there very good either