great review!
I use an older auzentech card in my htpc (x-plosion) and like it quite a bit for that purpose and was actively considering another for the car in the future.
Auzentechs have a bit of a following at the AVS forums so I thought I'd link 'em here for some more reading. I seem to remember someone did an comparision benchtest on one with stock and B/B opamps and there was quite a difference. If you need an analog out they're a worthy upgrade. I want to stay digital right to the decoder (reciever in the HTPCs case) so it's an irrelevant upgrade for me.
AVS forum is here
http://www.avsforum.com/avs-vb/index.php?
happy new year!