There was another thread all about this stuff that went on for 3 pages or so.
As an update, I was given a pot by a mate. He'd been given a free sample. I had to make up a temporary rig for flushing a central heating system, so I thought I'd try it out (as the place is a building site and a bit of liberated H2O wouldn't matter) anyway long story short it held up.
So I disconected the little rig I'd made and stuck a speedfit stop end on it. Then as I had it to hand I used the hydraulic tester and pumped it up to 1O bar. No leak.
I tried the joints for sheer strength by twisting with grips, pretty strong, the pipe twisted and the joint didnt fail. Finally I stuck a blow torch on the pipe and tried again.
The joints then came apart very quickly. I know, I had a lot of time on my hands that day, but I'd pumped the CH system up to test pressure after flushing and that was it for the day so thought what the hell.
It's actually pretty amazing stuff, but I could see problems if you were to solder a joint say 300mm within a 'just for copper joint' as the heat would travel down the pipe and could make the joint fail.
I personally won't be installing it in peoples houses, ever! Also if I was a DIYer, I think I'd stick too Speed Fit. So I don't really know where it sits in the market. It's a great product, but it's kind of pointless. Like reinventing the wheel.