I've finally tryed it during Easter (short) holidays.
I got 4 good windsurfing days, 2 with Screamer + R_type 7.8 and 2 with S-type + Edge 6.0
Well, I'm really happy with the purchase!
In full powered conditions the ST93 is really a rocket, fast, easy to jibe, smooth on the chop.
I liked it!
Some minor problems with the tacks but as soon as you get the key they're solved.
I was a bit worried about the 28 cm fin but I had no problems with spin outs or such this things: it did its duty!
Thanks again for the advice