I have to echo zherbus' sentiments on stax:
Playing Stax is like inviting your buddy over and making him watch you play Tetris. There's absolutely no fun in it for anyone but yourself. The game is even painful to watch from an outsider's point of view.
Also, Stax is the simplest deck to just destroy people with. Workshop-Trinisphere-go doesn't exactly require any real finesse. The deck forces a control player to hold a Force of Will and even so, the deck is certainly capable of vomiting out a Welder on the same turn. It is 22.5% of the Top 8's right now and I firmly believe that if Mishra's Workshop cost $25 like it did three years ago, it would be back on the restricted list.
Stax's application for this card is by far the more effective than that of Workshop aggro since it's a lot easier to recover from a Mox-Workshop-Juggernaut than it is to recover from a Workshop-Tangle Wire. Both Workshop aggro and Stax have access to Trinisphere, which is ultimately what's been earning the wins.
Well said.