I've thought that myself before, but having listened to it so many times I think the audience cheers are as much as a part of the album now

Totally agree. There are two or three distinct shouts from someone in the audience at the beginning of Around the World / Harder, Better, Faster, Stronger that are now part of my experience of listening to it. The audience is absolutely part of the energy of the album.

I've always wondered what the guy is shouting. Is it something in French, or just "Wow"?

For us french, it makes this song really weird, he's basically shouting the F word in french.

...I should’ve known better than to ask :)

All I would want out of a studio version is it panned to centre so that I could listen to it through headphones.