I've now watched a couple movies since painting the rest of my ceiling black, and the walls dark blue/black. I can't say I've really noticed an obvious improvement in picture quality, but the room stays darker(therefore less distracting), and I've actually found turning the iris down on my jvc to be a good thing now. before it just made the image look like it was losing pop. now, it's still bright enough, but it drastically reduces the amount of 'sparklies' and screen texture I see.
the downside, I find it much easier to see that black isn't black. i'm guessing my old 'bright' room was almost like bias lighting. it was bright enough it kept my irises more dilated and made blacks look blacker. with the new darker room, I guess my eyes are adjusting and fades to black don't look as dramatic as they used to. go figure
Displays: Samsung PN64F8500/JVC X35
AVR: Pioneer VSX-1130K, 7.1/5.1.2 audio
Sources: HTPC(Enby), PS3, XBOX360, Wii
Control: Harmony One