i have only bench tested mine so far, and yes, the EAX and the unit itself, does seem to gobble up about 30% proccessing power. Am yet to test it in the car, with a nice CPU and display card hogging visual plugin to really work it.
If i cant have my pretty visual plugin in my car... all because of some sound card my life will be lost! *sob*
altho, it is 24bit 6 chan.....comprimises comprimises! LOL