RE: What differences are there between versions 11.64 and 12.16?
I forgot to mention another related big difference for me in 12.02 from 11.64. In the compose new mail message screen in 11.64, I got unreadable black text on a black background. In 12.02, the color of the text came from my Windows color scheme, and I could read the text on my black background.
I tried Mocha_Dark and liked how it blended well blacks, whites, and shades of gray. I ran into the same problem with that skin as with others of Opera hardcoding numerous text colors black, making them unskinable, e.g. the text on the manage bookmarks page, and unreadable on a black background.
For weeks, I have been trying to move from 9.67, which had no problems with black backgrounds, to a later version of Opera. I have slowly got a system that is usable but frankly sucks. Some frequently used parts, such as bookmarks, require a non black background, I have concluded, and many less frequently used parts, e.g. the cookie manager dialog box, require a change of skin or Windows color scheme whenever needed.
I have been looking for an alternative bookmark system. So far I haven't had any success.