New version doesn't get along with vB 3.0.7 which is current stable version 99.9% of sites are using.
Also, IMHO it simply isn't sophisticated enough (yet). It doesn't handle bounces from the zillion of broken MTA's like qmail or MS Exchange which tend to spit DSN's in a plain text, completely omitting Final-Recipient and other handy headers. So new version has some room for improvement, too