I have been updating installs to r8.1 of eTrust. I updated it on my Mac OSX Powerbook. It works just fine on the laptop itself. One downside is that they have no pest patrol for OSX yet. So even if you are licensed for ITM you only get antivirus when you install it on your Mac. But better safe than sorry. I also have not had success yet getting a Mac client to go into the organization tree in the admin console. That is a headache if you have a number of Macs and a desire to run antivirus on them.
Something r8.1 did fix for me. I had very weird alerts coming from one site. Alerts for every cookie etc. Very annoying and it forced me to temporarily disable email alerts. Updating the server acting as the Alert Manager for that site group of clients to r8.1 fixed it though.