IMO I would steer clear of Audiocatalyst. I used to be a big believer in it - but no longer.

Pros:
1) Very Fast - even on an average Pentium ~333 it would do better than real time.
2) Very easy to setup and use.

Cons:
1) Sound quality isn't that crash hot I have discovered since getting my empeg. It seems to show up bad mp3s better than anything else - I don't know if that's good or not
2) Under XP I have found sometimes it doesn't rip the begining of a track correctly and I get a sharp noise for a fraction of a second - very annoying. Even under Win2k it seems to have produced some dodgy clicks and pops. This could be ripping or encoding.
3) CDDB -> ID3 tag support isn't fantastic. Bad filename characters (? * / etc) aren't used in the ID3, Years weren't used and lately I haven't been able to get it to make ID3v2 tags automatically, which meant I had to reprocess them later in DrTag when songnames were longer than 31-odd characters.

I have evaluated both CDex and EAC. I would recommend either but I have better success with ripping with CDex. For encoding I am now using LAME (-alt-preset standard) and I am quite happy with it. Best of all, the 3 are all free.

They are a bit harder to setup initially, but once you have that done, you're ready to roll.

I am now re-ripping my CDs gradually.