The gamma issues with network rendering I don't think were really a problem of BB, but I know this was worked on in 2013 along with the gamma issues with certain outputs like png. Both should be resolved now. There are over 500 legacy bug fixes in the 2013 release, the largest that I can remember, so look for a lot of little annoying things like this to be cleaned up. Not all of them but we did our best to find the ones users in general considered important.
We will continue to issue product updates for the 2012 release and potentially older ones. The first should be available on the FCS day of 2013 to enable the save to previous feature to work with 2013 files saved to 2012. There are other fixes in this update with more details to come soon, we are just putting the final wraps on it next week. 2013 does save to previous for 2012, 2011, and 2010 now. There likely will be a product update for 2011 and 2010 to better support this also. From this point forward save to previous will only support 3 versions back, therefore this will be the last release that saves to the 2010 format.