sixtyfive is one of the things I miss from when I was using Windows. God, I would kill for a Mac port of this (but I realize that's impossible).
I've tried UAD's and Waves' dbx emus, and to me, this one sounds the best, retaining the bottom end of the input and not collapsing into digital mush as quickly as the aforementioned—especially at high gain-reduction levels.
It's worth 10x its asking price. Cannot recommend it enough.