The slowness of the screen dimming is related to the graphics driver. Some are better (faster) than others. I have no idea why that is or why it would be so hard to write the driver to do that quickly, but that's just how it is. Personally I just disable the dimming. You can also enable password prompting as well if you want it to work like Mac/Linux (which IMO is how it should be - what's the point of adding one more "click OK to continue" prompt?)
Yeah, I disabled mine too. I should think something as powerful as a 5850 wouldn't have trouble. It also seems to make the HDD work a good bit, so maybe it does something else behind the scenes.
I'll probably try to find and turn on the password prompt, like OS X, as I agree that's how it should be. Is there a way to turn it off for some programs though? Like Core Temp and CPU Z always ask me.
