I just have the demo. I am waiting for the more experienced to try it, and evaluate it, before I drop $200 (that I don't have right now).
I use the demo on n-track. Mix down to 24 bit stereo and then put ozone on the master channnel. I really like the interface and it seems very good to me, but I don't know much.
I have a P-III 733 MHz with a dedicated 7200 HD for audio and it will run, but if I use all the built in options I run 60% to 70% cpu usage. The fact it works in 64 bit must really tax the processor.
I have tried the demo of T-racks and in my humble opinion ozone is MUCH better!