It would be nice if Creative had software with the same quality as their hardware. I started AH on Vista with the OpenAL fix for hardware acceleration, but it would really distort the Doppler effects that DirectX already distorts. Alchemy is at least a step forward, but you have to be aware which games you have that were written for OpenAL versus Alchemy, because there is a difference that you can hear on high end cards (maybe not so much on the ZS).
If you use Windows 7 with the Alchemy addon and then put in stereo sounds to AH you will probably discover that formations of bomber aircraft have distinct areas around them where the sound is either compressed (very audible) or where rarefaction (silencing) occurs. In other words, escorting bombers and flying around them the sound of the bombers is partially blocked just like a picket fence was built around them. OpenAL would over-compress the Doppler effects, but rarefaction never happened as far as my experience with it went.
The biggest problems I could see were with time difference of arrival, which is probably universal with anything that uses DirectX. For instance, if a P-51, or any other aircraft, is on the deck at the limit of its speed capability, then a listener on the ground should not hear it initially at the same distance that a listener would an airplane at 5k doing just 180 indicated. In AH a user will hear them both at 3.2k distance (give or take) whereas in real life the fast mover on the deck would be in gun range before you heard him coming. Alchemy more closely approaches this capability, but is still miles away from achieving it.
I don't think that there is anything HTC can do to more correctly portray these things. I think it is in the hands of Windows and your hardware. For some reason video games push the video and computing markets, but don't seem to have as much affect on the audio market. So, there is opportunity there for someone with enough money to affect a change.
