How much better a squat will apply to you as opposed to a leg press depends on how strict you keep your form during a squat... Don't bother doing that 405 lb 1/2 squat BS that you see most people doing in the gym. Try to get to parallel or lower, and concentrate on the quad/glute contraction, and try varying your foot width every now and then to switch the focus on each muscle group.
I just switched my leg workout Wednesday night... Started with heavy leg extensions 245x10 for 3 sets to get blood flowing (otherwise leg pressing or squatting would be uncomfortable and harder for my to get deep), and then proceed to do some plate loaded leg presses... I did 6 pyramidding sets... I don't remember how much I started with, I just know I went up to 700x5 for my 5th set, and finished with 400 for 12 or so... Then some dumbbell lunges, and finished with 1 legged squats on a non-counterweighted smith machine.
I couldn't walk right yesterday, and it's even worse today
Gotta love leg training like that.
Anyways, I'm an ex-powerlifter. I powerlifted for 1 year, but quit because of joint problems. I'm making the slow as hell transition to bodybuilding now... and let me tell you, it's hard to keep a strict diet
I'm 5'11", 215-220 lbs right now... My highest maxes were a 275 lb bench, 345 lb squat, and 425 lb deadlift a little bit before I turned 17. I was a bit heavier then though, close to 230 lbs. I no longer give a damn about my maxes, and enjoy working towards hypertrophy much more now.