I don't have any advice on getting demo sets (I'd love to try a Mach demo set if I could), but I switched from P2.9s to a pair of 3S pads a little less than a year ago. I was overall happy with my P2.9 pads, but I was forced to replace them when they got ruined in a basement flood. I decided to try out the Bauers. They're a LOT stiffer, give much bigger rebounds, and are such much better and consistent when it comes to sliding. I haven't used Hyperlite/3X pads, but I'm sure the same would apply there too. Took me a while to get used to them and figure out strapping, but right now I'm really digging the set up.
Oh, also, they pull the pay way up. So it makes the lack of additional thigh rise no longer an issue.