So, I've been using coolhand for 3 days now, and I have to say that it is incredibly easy to memorize and remember the key placements. The base keys only took basically a single pass through to remember, and the symbol keys are only slightly more effort due to the sensible mirroring.
I also find that using only "easy" and "stable" chords increases my speed dramatically. My speed is already back up to where it was after a lot more practice with some of the other layouts. (I do use the strap, but with this layout it does not need to be very tight - mostly its just there to hold the twiddler loosely in place).
In the interests of full disclosure, I'm not using the MCCs. I have some doubts in general as to whether the increased cognitive load generated by MCCs is worth it for shorter key sequences, but I think I'll leave those thoughts for a separate post.