We also use backup Exec (11d, but 12 is out now) and I am relatively happy with it. But there are nights when I want to just tear it off my servers and send the 1's and 0's back to Symantec in a box...
Most of the frustration with the product came during the Symantec buy out and getting used to the confusing and archaic licensing/upgrade scheme that Symantec put in place.
There is also a serious lack of straight forward, easy to use, information about the product on their website. For example, I defy anyone to go to symantec.com right now and show me a document that clearly outlines what the upgrade and patch history of version 11d has been. Doesn't exist, you are on your own.
Support is almost completely phone based (out of India it seems which is a red flag for me) but has been responsive.
Even with all of that, and also considering it has a feature set that is well over what we need, in the end this has been the easiest, most reliable backup software we've tried.