OK I just tried Bitdefender 2012 Total security, and here are my thoughts.
While Bitdefender routinely gets high marks in AV tests, I can't really recommend this latest iteration. It suffers from the same problem that Kaspersky had.....that is, the performance hit on your system is simply unacceptable. It started with the installation, which took perhaps 5 minutes to complete, compared to Norton's 20 seconds.
However, Bitdefender also did a pre-scan to make sure I did not have any malware, and it also downloaded most of the installation files from a server, but the installation size was obviously quite big.
Something else I didn't like, you cannot have MBAM installed with Bitdefender
. Apparently, the two conflict with each other, so if you have MBAM installed, then Bitdefender will ask you to uninstall it.
Norton and MBAM have no such conflicts.
My boot up time and browsing speed was noticeably slower with Bitdefender installed, compared to NIS 2012.....though not as slow as with Kaspersky. As for scanning speed and resource usage, both were quite good. I did a full scan in approximately 13 minutes (main drive has over 220GB of data), and general memory usage was low.
In the end, I ended up uninstalling Bitdefender (even that took a few minutes!) and switching back to NIS 2012. The advantages Bitdefender possesses over Norton such as a slightly better on demand scanning and heuristics etc aren't enough to make me turn a blind eye to the performance hit it incurs.
And Norton has it's own advantages, such as a much smaller performance hit and better overall protection, according to AV-Comparatives at the least. At any rate, NIS 2012 is brand new and still has a few bugs to iron out. It will only get better as time goes by, so I've made up my mind to stick with it