White Lightening, I know where you are coming from. Believe me! I'm a trainer, and I see all sorts of funny stuff on our Leg Presses! I know what correct form is, and I know what my body is capable of. Honestly, I tried "going deep" on our Leg Press, and I felt my back and tail bone come WAY off the pads, and I actually felt my back torque.... and OUCH!!!!!!!
So, no matter the weight, I know how far my beat up body can go. I have decent range of motion with "all that weight", and yes I can do it! I was somewhat gifted with leg strength. Since playing most sports growing up, mostly soccer, I've always had strong legs and calves. I will say this though, on certain leg work outs, I give up the "meathead" tendencies on Hack Squat, and go past parallel, like Jay Cutler does in his new DVD, just not as much weight, obviously. Somedays, I do go really heavy, and just 90 degrees.. some days, PAST!!!
I also heard about Ronnie's leg work outs. Such as his true DEEP squats with 8XX lbs
And how he loads up a Bar and a 45 on each side (135 lbs) and he does Walking Lunges up and down his street... a long street!!
I do agree with you, but I know my limits, and I'm smart about it. I've learned from my mistakes as a young lifter!