I have tried the 10m, 9m and 8m and found the following points;
(1) The sails are anything from 1 to 2 kg lighter (static weight) than the Reflexes /Mach1 of similar size. The luff tube is made of a light weight laminate and a dacron - type material saving most of the weight I think.
(2) The sails are based on a modified Overdrive frame, using 4 short length inducers. The battens are quite stiff giving quite a flat exhaust after the initial camber.
(3) The leach is not as "loose" as the comparable slalom/race type sails but the sail still has a nice twist.
(4) Rigging is easy although the bottom inducer is quite heavily loaded. I removed all spacers from the bottom inducer and found I needed to add spacers to inducer 2 & 3. I think when the sails stretch a bit (particularly the dacron-type luff material) rotation and inducer loading will even out a bit.
(5) The sails feel quite different to the looser leached Mach1's. They are probably aimed at the lighter end of the normal wind range for the sizes. The low end power is strong and pumping works very efficiently. There is a definite sense that the higher parts of the sail are generating more power than the slalom type sails and I have found that I've needed to move the harness lines back a bit, and as Darryl says move the mast track a bit.
(6) The biggest difference is the amount of vertical lift the sails generate - I feel with these sails I can rake my body out and roll the board to windward much better than with the slalom-type sails. The tendency of the nose of the board to dip down when rolled to windward is much less with the sails - which I put down to good vertical lift from the sail counteracting the reduced lift from the tilted foil. What this means is that the upwind angle is better - which is good news for racing!

I found that the 10m became quite heavy-feeling when the wind pushed over 14 knots - hard to find good balance, but I suppose it is designed for the 6- 12 knot range. I've only had the 9m out once - in about 10-12 knots and it felt sweet. I used the 8m in the recent champs , up to about 20 knots and again it felt nice, particularly upwind.
More testing/using is required to get a better sense of these sails but first impressions are quite good.
10m - rigged best on a 490 Apex with 40cm fixed extension
9m - rigged on 490 Apex
8m - rigged on a 460 Apex
[sorry for the rotated photos - not sure how to fix that!]
10m
8m

9m