I've got both of them, and I can tell you this much: the Stax are a heck of a lot prettier. Apparently the Stax used to have a ton of mistakes, so I contacted the guy who runs the company about that. The newest version has corrected most of them, so I figured I'd take the plunge. I'm taking the test this summer, so as far as content, I'm not exactly sure - I'm going to use both, since I haven't heard enough feedback regarding the Stax. The decks seem to be tried and true, so I'm hesitant to try solely the Stax.