This is my first concert blu-ray, so I did not know what to expect. I was positively surprised by the great picture quality and the sound - probably better than being there... except for the atmosphere with lots of fans all around you. I watched the concert on a large picture (short distance to screen with a 720p projector) and a decent 5.1 sound system fed by a PS3.
The bands play for the most part separately, but also play some songs together. There are chapter marks for each song, so you may jump to the next/previous song if you want to. There is a separate scene with a "drum challenge" between the drummers of the bands, but this scene has a smaller picture with lower quality. I have not viewed the concert continuously from start to finish, but listened to a handful complete tracks and smaller parts of the rest. I almost cannot wait to sit down and get the full concert - planning to arrange it with wife and kids (old teenagers) watching. As you probably have guessed, I like both Chicago and Earth, Wind & Fire.