The major differences is OpenWrt update to r38031 and update Cgminer to latest(Version: 3.4.3 Latest commit: d5f61e9, Sep 22 2013) you can see that at the ChangeLog 
https://en.bitcoin.it/wiki/Avalon#20130923
https://en.bitcoin.it/wiki/Avalon#20130923
Thanks Xiangfu! My question is what are the major differences between ckolivas' 20130821 and this new xiangfu 20130923? I did run xiangfu's 20130723 for a bit on my Batch 3 just fine, but I've been happy with 20130821 so I am not exactly itching to change...
Seem like both Xiangfu and cklovias use OpenWRT r37008 but the new one upgrades cgminer 3.4.0 to 3.4.4?
Seem like both Xiangfu and cklovias use OpenWRT r37008 but the new one upgrades cgminer 3.4.0 to 3.4.4?