One of the best ideas I ever had. Caps Lock is one of the biggest keys on my keyboard and close to the rest. It would be a waste to use it for a single, rarely-used function.
Now, I could dmap ctrl-l to esc. But I'm so used to the high-left pivot for 'esc' on Thinkpad keypads (and it's a tall key making for an easier target) that it's not worth the bother.