A few years back I was struggling along on the 550. It was tough. Then they released the 548, which didn't work well for me and didn't help. Then I got 590, and it was a bit better. Still quite difficult but I learned flying gybes on it and was trying footswitches to some success.
Them 633 came and that was huge advance and allowed me to learn a lot.
The 590 I still had big problems with sea grass, which we have a lot of. Only one or two strands on the wing and it won't fly. 633 would.
Moses was so slow in developing good high aspect , large area wings I gave up on them.
I was looking forward to the phantasm foils, but its taking too long, they haven't rolled out all the wings. So im waiting.