First, I'd like to say that in general, I do like the card, it's a nice step up from the X-FI card I had previously.
When I first got Max Payne 3, it worked great.
I was playing around in the ASus Phoebus control panel, and then a couple days later I tried playing Max Payne 3 again. It downloaded an update from Rockstar's site.
After the update, nothing in the game worked (sound worked in some cutscenes, but not in-game and title screen, and I couldn't even move in the game (the animation for movement worked, but I wasn't moving anywhere).
I tried reinstalling the game, and still same thing.
finally, I went to the Asus Control Panel, and desparate, I turned off GX, and it worked.
Note that there is an audio section in the control panel where you can set stero, or surround, and those settings didn't make a difference either until I turned off GX.
So my suggestion to users is to NEVER have GX enabled unless you absolutely have to (I believe for older games).
it would be nice if the asus control panel is "set it and forget it", but it looks like unfortunately you have to tweak it a lot.