[syslog-ng]difference between 1.6.4 & 1.7.0 branches?

hi, can someone clarify the difference between the 1.6.4 & 1.7.0 branches? the 1.7.0 branch doesn't seem to have been touched for awhile, but the 1.6.4 branch seems current ... syslog-ng-1.6.4+20040710.tar.gz 07/10/2004 syslog-ng-1.7.0+20040514.tar.gz 05/14/2004 i'm building on OSX 10.3.4, and have read others have used 1.7.0 .... is there a reason? which branch is 'best'? thanks! richard