So a year after this batch of testing was done, another golf forum is doing a similar forum-member testing of the My Tour and Get Sum balls, and I've been selected to participate. After reading all the comments here, I'm even more excited to get some of these to try out.
I'll be in Ireland for 2 weeks in June. I'm hoping for good weather, but I'm sure we'll have at least a bit of rain while we're there. That's probably going to be the big test. And I've read that you can use the same air-gun technique for almost any grip out there, good news if you've invested in a compressor.
I learned Aimpoint Express by buying the video on their site, buying a level and then practicing the technique. That worked for me. I may still take a clinic somewhere down the line. I'd have to travel a bit to take a clinic.
The nice thing about the video is I can watch time and time again.