I try to be as short as possible.
First of all I am really a stickler in audio quality point of view. :)
Rock in Rio became my favourite due to the sound and visual qulity.
The camera work is nice, You can feel the concert atmosphere while watching it.
About the audio part:
The center channel is for Adrian`s guitar, which was a good idea. The surround channels makes the concert totally live.
The sound is dynamic, loud, unified and clear. The DTS sound is better, than Dolby. And You can hear the difference, and I mean it.
This concert-sound differs a bit from the well known maiden sound. Better, much better. It is outstanding.