vim users (and I am one!) ^[ strictly dominates escape: it doesn't force you to move your left hand up or rotate at the wrist. Does emacs use escape? What else does?
I really hate using esc in its default position so I always map caps lock to esc. Mapping caps lock to ctrl seems so much more useful; I had no idea ^[ is the same thing.
Also, remap that fat caps lock key to control.