fro, whoever wrote that article i guarantee you is standing on pool cues. let's say for argument's sake that there is equal stress placed on the glutes, hams, and quads for smith machine and free weight squats. what they did not take into account was the release of GH by your body during these exercises. we all know that it's a little bit easier to do a smith machine movement than a free weight with the same weight. the added benefit to not having something stabilizing you, is that you're straining harder to keep everything in balance while at the same time pushing. this will in turn will make for a larger GH release. that's why people are always raving about deads and squats being great for your arms is due to that growth promoting release. bottom line is, you're not helping yourself out by convincing yourself that smith machine squats are just as good as free weight squats. if you want to go the safe route and not grow as much, by all means get int that smith machine and hammer out "squats." but if you want your legs to blow up, lose the training wheels.