Personally, I'll lift until I cannot lift anymore. It's about making my body look great, sculpting it until I'm ripped. I don't need the bodybuilding think look. If you don't want to increase your size, and don't think it will do you any good, don't do it. It's a preference, not a must. Personally I think power comes from your core, as well as your legs. To have a strong core, you need to be doing abs and back work (weighted crunches, dead lifts). Your legs... on the other hand, you can get very strong legs by doing Hindu Squats. I don't think the way you're doing it is bad, perhaps you just need a little more info to make it right. Check this out. http://www.mattfurey.com/