GroupWise Design Recommendations

I am working on an upgrade project for my current GroupWise 6.5
environment, and I wanted to get some opinions on virtualizing it. I will
be upgrading to GW7 or 8, and replacing all of the server hardware.
Currently I have a 5 Post Office system with 1 WebAccess agent, 1 GWIA, 1
Primary Domain and 3 Secondary Doms.

Each PO is running on it's own server, the WebAccess agent & it's Secondary
Dom are running on their own server, and the GWIA and it's Secondary Dom
are running on the same server as the Primary Dom and the 3rd Secondary Dom
(routing MTA for PO's).

The PO's are all running in online mode only, hosting about 2000 mailboxes
each (10,000 total). We do not use a Document Library, just email and
calendaring. We also have a BES server hosting about 150 users, which adds
to the Post Office load.

My question is this. I have read a lot of mixed reviews on the topic of
putting GroupWise into a virtual environment because of it's high I/O
utilization. Has anyone with a comparible GW system tried virtualing it?
Are there any performance hits? If you were successful, how is your
virtual environment setup?

Thank you,
Laurie