013, Tilburg is a possible location for filming as well. Many shows have been recorded there and The Netherlands are a good market for DT.
The reason why there is no proper live version of The Glass Prison? My guess is that it's one of the hardest songs to play, especially with those guitar apeggio's at the beginning. Petrucci has mentioned that part as very difficult for him to play, because Rudess wrote them on keyboard (look at that making of video: Rudess' fingers are widely spread, almost alien like!). And Petrucci, being a perfectionist, probably is not too keen to have that song filmed live.
And didn't Myung (jokingly) fall from his chair after recording TGP? If I remember correctly, that was also part of the making of TGP as part of those making of movies for SDOIT - which I really liked (especially seeing Rudess playing a great keyboard part in the making of Misunderstood, but I've never heard those brutal strings back in the final mix, sadly enough...).