Absolutley, the best thing to do is a less effective, more dangerous version of the lift.
I was thinking the same thing..if you look at a stiff leg'd deadlift..the bar just doesn't move straight up and down, it follows the line of the body. A SMITH MACHINE is straight up and down movement set on a fixed plane.. if you do it even close to being right you won't get full extension nor will you get a lockout.
Next time still a bar off the benches and do them in the gym floor. The more I think about the smith machine the more disgusted I become with it. Only good if you have to rehab and injury or are working alone and still to bitch to work in a cage.