I’ve just downloaded Creative ALchemy from here. I install the Windows Vista with X-Fi Elite Pro and F.E.A.R.

Screenshot above shows the F.E.A.R on Vista. Hey? All the HW acceleration and EAX function are not available!

Run your ALchemy. It will detect the games on your system. Choose F.E.A.R and “transmutes” it to OpenAL.

Run your F.E.A.R again and see all the options are available! Turn them ON and hear the differents!

In my opinion:
So far, the ALchemy is a good solution for you who want to run EAX and hardware acceleration on X-Fi and Vista. Currently Vista only supports OpenAL not DirectSound/DirectSound3D and no EAX. All sound card and game which support OpenAL should experience no problem with Vista. But the others will experience problem (without DirectSound/DirectSound3D and EAX, it will support stereo channel and no hardware acceleration). So, ALchemy will work as a wrapper for X-Fi and EAX in Vista. Remember, only X-Fi with CA20K1 are supported (so remove X-Fi Xtreme Audio and Xmod from your list). Creative says that they will consider to provide ALchemy for Audigy series, perhaps in the future, but they can’t guarantee about it.