fireware upgrade k750i

Whic is the latest and best fireware for k750i

Recently i am using R1BC002 EMEA_7

R1DB001 is whitout battery bug, I think that the latest firmware is R1AA008 but I'm not sure

Most popular is R1CA021. The newest one is R1DB001 :)
And as I know, battery bug has only w800i firmware;)

R1db001........

What kind of battery bug in in the W800 sw?

R1CA021 will decrease all volumes compare to R1DB001.

I think R1DB001 is better than R1CA021 if you don't upgrade Acoustics pack.