http://www.nphoto.net/news/2014-07/17/1eacb1337aaccb89.shtml
(in Simplified Chinese)
The test picture crops are with f-stops marked. Left side ones are with new firmware, with diffraction reduction enabled. Right side ones are with the last firmware of version 1.03.
It seems that at very large apertures, image sharpness is affected somehow. But reversely, at mid to small apertures, sharpness does have been improved. Anyway, I blog, you measurbate and then decide! ;-)
Nonetheless, if you are a K-3 user and would like to update and try, the official firmware download link is as follows:
http://www.ricoh-imaging.co.jp/english/support/digital/k3_s.html