While some free A/V's can be as good or better than SOME paid A/V's, just because it finds something others miss doesnt make it better, it could just be an instance of finding a FALSE positive and the others didnt pick it up because it is false , Avira might very well be the best free A/V on the market , You would be hard pressed to say its actually better than ESET'S NOD32 or Kaspersky, Norton etc , ESET is the ONLY antivirus technology that has not missed an "in-the-wild” virus in Virus Bulletin VB 100 testing over the past nine years
ESET has achieved 51 Virus Bulletin VB100 Awards, more than any other vendor.
In Virus Bulletin's comparative tests, ESET NOD32 Antivirus has not missed an 'In the Wild' virus sample since May 1998.
and from http://www.av-comparatives.org/
In an independent test by AV-Comparatives, ESET NOD32 Antivirus has consistently achieved
the best results among all tested brands. "ESET NOD32 Antivirus is the leader in Advanced+ awards,
having received top honors in each of the last five tests. This represents the most proactive malware
detection capabilities of all the products tested over the last 12 months."