I upgraded from Symantec 10.x Enterprise, to the Multi Tier. It is a major upgrade different console, different looking client. But you can change all the setting based on policy, so you can turn off all the extra junk.
I have it installed on about 10 of the 300 computers here. There is no differnet server Vs. Client install now all the same. I have been using this product since Intel owned it and this is the biggest change in an upgrade I have seen. Sorta like the SMS smtp Gateway 4.0 to 5.0 upgrade.