I'm not the GP, but for what it's worth I do remap capslock to esc. I mostly use a Kinesis Advantage keyboard where the escape key is one of the chiclet rubber keys, so using vim (at all) really begs for either a remapped esc or brain-retraining to use ctrl-[.

I'm not sure if it's a better or worse choice to remap capslock to ctrl - but it's certainly viable. The old Sun keyboards used to have that layout...