i read a very interesting article in some magazine (i forget which). i'll paraphrase the idea :
when you tire on an exercise (BB/DB bench), its not your muscles getting tired of moving the weights, but rather the stabilizer muscles (rotator cuff) that's making you stall out. the hypothesis therefore is to exercise on BB/DB bench until you hit failure, then hit the smith machine up using the same weight or more, and run that till failure.
this is similar obviously to drop sets, but you're using either the same or sometimes more weight on the smith.
on paper this sounds like it makes sense for mass, but on paper all kinds of things look great - even origami. any thoughts on this, or anyone that has used it?