I hear what Matt's trying to say, and if he feels smith machine squats are better for HIM, then I wouldn't argue.
However, it sounds a little too much like an excuse as to not go HARD on leg day.
Regular squat is king.
Its not an excuse and i do go hard. I start at 1 plate a side and do 30 reps, 2 plates 15 reps, 3 plates 12 reps, 4 plates 12 reps. Then drop it down 3 plates 15 reps, 2 plates 20 reps, 1 plate 50 reps. Try that your legs will be soooo pumped!, then its off to the hack squat, then single leg leg press.