Thanks again Dave, this was really interesting. I have definitely changed the way I tamp after using it. My tamp is now much slower and lighter, with the grind a little finer. Not a huge difference, but better...
If I didn't already have a nice tamper, I would certainly entertain the thought of using this one permanently.
I seem to be the last of a short chain, you guys have until Monday to check it out and get on the list, otherwise it goes home!