Se for yourselves, PhysX is no "gimmick". It adds a lot to the level of immersion while playing the game, and only NVIDIA DX11 card owners will get the full experience of this game.
Game critics agree with me that it's a lot of fun.
This what I mean when I say ATi users lock themselves out of what high end gaming has become- you get no PhysX, and this game is optomised for 3D Vision as well.
This stuff transcends brand loyalty IMO- buying an ATi card now is just too limiting. ATi is doing nothing to advance the computer gaming experience.