The external coating material is just an anodize. All 3 version are anodized aluminum. The only difference is the color of the dye they use in the anodization process.
If anyone can hear the difference based on the color of the dye, they must have extraordinary hearing. Hopefully they weren't offended by my comments.
PS: Thanks for updating your post with your experience swapping the batteries.
Some person may extraordinary hearing like you said or their reference system is good enough to show the diff
Even it minor, I am still stand behind them and respect their hearing.
Please try it yourself or check with one of your big fan customer who recently sent his black ak100 for rwak100s but keep the gold ak100.
I think we should stop here since it is not related to you or my mod and you also do not hear it yourself yet. I just want to show them it is not battery matter so many people not ask for changing gold battery.
Edited by Birdoffice - 6/30/13 at 8:10pm