I received my THRILLER X4 17sqm since almost 2 months now and I want to clarify some things about this new wing.
As told on the U-Turn website: -the THRILLER X4 is a first class competition wing for pilots with acro experience and competition pilots-.
It means that it is not a good glider to learn basics acro maneuvers as Stall, Spins, Wing Overs, Sat and Helicos. I even recommend you to already know how to do Helico connections before to buy and X4 in small sizes (18sqm and under, depending of your air charge).
Why? Because the X4 is an high level acro glider, nothing to compare with the last generations of U-Turn acro wings (2k11, 2k12, X3) and other passive acro gliders from other brands.
While flying with the previous acro generation, I could remark practically no shoot in stall exits and that the gliders were very slow in Helico and in connections (Heli to Sat to Heli). The gliders were very heavy to inflate and the brake pressure was very high.
The X4 is completely different. You have to brake the shoot from stall exits and it is super fast in Helico and in connections (Heli to Sat to Heli). It is lighter to inflate because of fewer rigifoils and the brake pressure is also lighter, which makes your arms less tired after maneuvers.
With a low air charge (arround 4,5 kg/sqm), I think the X4 could even be a very good fast Freestyle glider: good to learn Heli conections and Rythmic Sat to Infinity Tumbling.
With bigger air charges (over 5 kg/sqm), I only recommend the X4 to people who already masters some of the principals Heli connections (Mysti to Heli to Sat to Heli to Heli) and even Infinity Tumbling.
The X4 is principally for people who want a fast glider that is working in all maneuvers.
Personally, I love the fast Helico connections, the glide ratio and the fact that it is also working well in Espheras. What can be better than a wing working well in every maneuvers and that has a very good glide ratio?
The best advice I can give you is to try it to see the X4 dynamics by yourself.