As you can see on the last tests of AV-Comparatives Avast 2015 is doing pretty well 
http://www.av-comparatives.org/wp-content/uploads/2014/12/avc_prot_2014b_en.pdf
Very Nice Glad to see that
We will see better results in upcoming months,considering this feature has come in just now:
https://forum.avast.com/index.php?topic=163221.0
Read:
http://www.wilderssecurity.com/threads/how-avast-is-performing-these-days.371019/#post-2437926
although it still needs some final polish to get to the 100%... will be interesting to watch the results from more sources and across a longer period of time.
One problem I see with this newest protection scheme is how to allow utilities that
by their nature can’t or don’t meet the criteria required but aren’t malware.
There will have to be a way to use these tools without having to remove Avast.
avast! also scored really well in latest Dennis Labs test, beating even BitDefender and Trend Micro. Not there yet, but it seems to be finally moving up there again…