Well, Audyssey can sound as great as Dirac Live, but it does require a lot more work. However, once you get it sounding great, you get the benefit of having proper Loudness Compensation (Dynamic EQ) and state of the art Dynamic Range Compression (Dynamic Volume), both of which Dirac Live lacks.
IMAX Enhanced is both a certification program - like THX was in the "good old days" - as well as additional sound processing overlaid over DTS and DTS:X soundtracks. Some of these soundtracks in fact will have a flag that will trip this additional sound processing. Let's see what the issues are then!