It seems that the new Avira Antivir Personal 10 bugs allot of people. Indeed Antivir has a high fp rate. In this case adding files to the exclusion list should be easier. There is a action called "Always Ignore" that is misleading... it actually allows you to ignore a file until you reboot. The short scan after every detection is annoying for some users and it is not always needed (it happens even with eicar test file). Updates are still problematic for some. I recently had to re-install Avira because notifications wouldn't pop-up anymore.
Avast 5 is a big improvement over the previous versions. It has nice features (like the behavior shield and the web shield) but in most tests Avira has higher detection rates.