I know machines are the tools of the devil and all but I really feel my quads working when I do these. Usually I'll follow my squats/front squats with the 45° leg press machine but someone was on it tonight and I, not wanting to wait for him to finish, saw that the hack squat machine was free and decided to try it. It reminded me of the feeling I get from doing front squats in that I feel almost all of the load being placed on the quads.
One question though for anyone who does these is where do you place your feet? Like straight out in front, making your whole body a straight line or a little bit in front of your upper torso, making a slight angle at your waist?