Dr McGill has a study showing how shitty the 45 degree leg press done with excessive rom and tard reps is on the lower back, it's brutal
I went so far as to buy a Hammer strength horizontal press for my home gym because all the local gyms only have 45 degree sleds 
IMO the safest one I've used is the nautilus xpload because you can start from the top, you can out the seat back so it's almost a squat, and the footplate has linkage that saves the knees .. But it was twice the price of a craigslist HS press so I took the next best thing
I'm a huge fan of A. Jones and anything he had his hand in were superior.
That's why I put a lot of trust in Hammer equipment though I don't know how close his son is to his father's genius.
Recently our gym got a Hammer V Squat. As soon as I tried it I didn't like it and was so disappointed that the son of Arthur Jones would produce a squat machine that literally prevents you from doing a full squat. A.J. was a strong proponent of full range motion and it's impossible to go past parallel on the Hammer V Squat.
But after reading that study about the efficacy of parallel squats I gave it another try. It definitely gives me a pump in the quads that no other movement does.
I'll stick with it for a bit and see how it goes. Regrettably, when they got that machine they got rid of the Hack Squat.