I played the 360 version in Game recently, and was surprised to find there is a noticable difference between the two versions.
I own the PS3 version and had only just recently completed it, so it's visuals were still fresh in my memory.
The 360 version appears to have some slightly strange texturing on walls, and other surroundings. It doesn't necessarily look bad, but it doesn't look as realistic as the PS3 version. I also noticed that it is definetly brighter, not hugely so, but as you already stated usually dark areas are lit up.
I would have to see the two versions running side by side to make a better analysis, but to my eyes the PS3 version is the superior version graphically.








