Personally, though, I don't find the worst strain comes from the placement of Ctrl. The worst comes from the awful staggered layout of keyboards that serves no purpose save for a long chain of HCI backwards compatibility with the typewriter. I hope someday keyboards like the TEK (which, incidentally, gives a perfect spot for Alt or Ctrl under the left thumb) become more commonplace, or eye movement-based systems supplant the use of one's hands for focus control.