Aureal Vortex (2) is a bit overrated. I searched for it for about a year and bought it for a decent price. I thought that I finally hear what everyone was so excited about. Tested it with most A3D 2.0 games and I will tell you something... its just a big MEEEHHHH...
Ok, the HRTF is very natural and sounds cool but theres no reverb at all. You can of course have EAX 1.0 with v2048 drivers but it sounds so terrible that you will want to turn it off as fast as you turned it on. Really - A3D 2.0 is nothing special. It will make you WOW when you hear it for the first time but nothing more.
What I want to say is that the A3D sound tech is very accurate, sounds GREAT and different than everything else BUT without room reverbs its just unnatural. It doesnt sound as I expected.
Finally I decided to install back my good old Audigy 2 ZS with great EAX support and use the default direct3d sound or A3D wrapper drivers. I think that human ear is more for reverb than HRTF sound. Not to mention that there are more games with EAX support than A3D.
Overall Im very lucky that I didnt pay for it so much as other people did. Im sure I'd regret it if I pay so high!