Newsflash: If Sram, Campy or Shimano is going to charge $2K+ for a group, you friggin BETTER be able to ride in the 53 x 25, or what's the point? I do it all the time. Well within the tolerances of modern high end components.

'Cross chaining'. What is this the early 80's?

Let's have a discussion about toe clips and bar end shifters next. Then we can all go to the friggin Rivendell website and sing Kum Bay Ya.