CrossRail is indeed one of the most exciting urban transportation projects going on for me right now. If anyone is interested the BBC made a three-part documentary on it:
www.youtube.com/embed/ITcQMiJkppM
Do you mind posting a link? I've only found some old plans from 2009. Now that the second platform construction is wrapping up, I myself am becoming more interested in what is to become of the Union Loop.