SB X3's head shape customizable Super X-Fi HRTF could certainly help to accuracy over usual average head shape based HRTF.
Tough that actual sound card hardware part of D/A converter and headphone amplifier isn't at level of price sticker.
(but still clear step up phone/tablet level chip in GSX)
But that would be still enough enough for GSP 500 and Creative has B-stock at lot more reasonable price.
But B-stock Sound BlasterX G6 with only average headshape based HRTF is still cheaper and has better D/A converter and lot better headphone amplifier enough for most headphones you could buy.