I took my 5D Mark II to the Asian Game Show for testing last month. I happened to be around when Sony held the Playstation Girl beauty pageant. With the makeshift stage and mediocre stage lighting, I think it was a good test for shooting in some less than ideal condition. All the photos were shot in RAW with 5D Mark II, EF 70-200mm f/2.8L IS USM and 580EX and Cloud Lightsphere II + Amber dome. The RAW files were converted to jpeg with Lightroom. You can click on the photos for a full resolution view.
I am very pleased with the image quality of the 5D Mark II. You can read my full review of this camera here if you have not read it yet.