I don't do squats or dead lifts because I do not have perfect form and don't want to injure my back. So I just do the inclined leg press and calf raises for my lower body workout (and my quads have gotten pretty big). I'm also having pretty good gains on the leg press (along with bench and other exercises). Now some people say you can seriously hurt your back on the leg press but I think that is caused by not keeping your back flat on the backrest and going way too low (knees touching the chest).
So I guess in short, for someone who is concentrating on chest, shoulders, and arms... isn't the leg press (and calf raises) good enough for the lower body workout? I don't really care much for the squat either, it is one of my least enjoyable exercises.