Outlaw - it is basically a smith but the forward and back movement is to create the movement of a free squat (or whatever exercise you are doing with it) byt not having the bar moving in a fixed plane so allowing the bar to travel in a better ROM yet still with the safety of a smith. We found it when looking for equipment:
www.ironcompany.com
Midstar - I agree totally. Especially with cardio and machine type equipment as they can all differ greatly in how they feel, Trying it out will definately be the plan if we get it!