I don't know about a good review place, but if you are thinking about buying one of these cards
*dev screams*: TERRATEC!!
I suppose you wonder about the 24bit/96KHz features of both? The Audigy does NOT have 24/96 except for in DVD playback, but the EWX has recording/playback in 24/96. The terratec is not a gaming card. Stereo only, no 3d sounds etc. For music it's excellent though and one of the greats.
I don't think anyone would do a comparison for these two cards as they are not aimed at the same kind of users. EWX is a music card through and through, but the Audigy is a general home user card. Hope this helps,