If I may tempt you into parting with your hard earned money...
I can tell you this: each wing has a very different character, and you might be very much surprised to find something you like, but a lot, in addition to your M Curve.
Plus, it is also very nice to "switch" every once in a while, both to suit conditions, mood, level of physical preparation, and to train different aspects of riding (imho, of course).
My experience with Gong:
* Veloce M: it is a fast wing, super carvy and playful, quite difficult to tame with the Fast 40 stab. It will accept tight turns at speed, getting out of them like a bullet, is a blast very powered in waves, but with the Fast40 it wants lots of front foot pressure to go fast, and is very yaw unstable. Never dared to go over 19 knots with that combo, as you really need to push the front (at my weight!) and the darned foil wiggles under your feet all the time... but exciting for sure! It loses *much* less speed to drag than the Curves, say, when you footswitch, gybe or tack. Did not have the Veloce stabs with it, so no first hand experience, but should pair perfectly with the Veloce 39m, which removes front pressure need, and gives it much needed yaw control.
Sold it, as it stalled too abruptly for my weight, but: when it stalls, you just pump it and it recovers. Cool.
* Veloce L: my preferred wing before the Fluid. Much more sedated than the M+Fast40, but same DNA: it accelerates quickly, loads of lift, stalls abruptly but quick to recover. Much, much fun, and surfy. With the Veloce 43 stab it is "strange", apparently stable but weirdly reactive. With the Veloce 39 it is just fun. Still have to test it with the Fast 40. Maybe it will be like the M? Still, the Veloce gives you the impression of sliding a bit in the water in certain manouvers, like you can "twist" it in the water when speed and angles are not too pronounced (i.e. duck-tacking).
* Fluid L: perfect compromise between the curve and the veloce. Compared to the Curve, it glides a lot more, and responds to pumping like a Veloce. Compared to the Veloce, it has a bit less glide and acceleration, but: when you curve, you feel like you are on tracks. Amazing feeling that will bend your knees. With the Fluid 40 it is strange: lots of "early" resistance to begin roll, but then it is super loose. Stall similar to the Veloce L, same recovery. Different to the L Veloce, even with more limited speed/angle, it always feels like it is "gripping" the water, no slide.
* Fluid L-S: stalls earlier than the L, and is less roll stable. But funnier to ride! Paired with the Fast 40 it is very, very loose: the foil "shakes" under your feet, but it is fast and really fun to ride once you adapt to it. My currently preferred ride, even though it is the most muscular of all, as it requires continuous micro-corrections.
Curve L: big, reassuring, lots of support, docile stall, but zero pumping, so when it stalls it is often game over. Loses lots of speed without power, carves well. With Rise 45 it is crazy stable, even in nightmarish conditions (2+m of wave, whitewater). With the Fast 40 it is good fun, especially in the waves.
Curve M-T: a bit more "glidey" than the L, but more abrupt stall. The wing I liked the least, to be honest.
So, at your level, I would most certainly test a Veloce M (with a Veloce 39 stab) or a Fluid M. Or even the new Fluid M-S, which must be crazy fun in carving!
As to the Fast/(new)Curve stabs: I truly wish to try the new curve, as it fits into the kite section, so it ought to be fast and lose just with enough tracking to make things easier on the waves (I am no Malo or Beryl, I'll get help if possible! )
As to the other stabs: *all* of them can be used, and some of them are actually good fun (i.e. Fluid L-S with Fluid 40, or Veloce L with Veloce 39). The fact is, the Fast40 is the "loosest", so you sacrifice a lot of control just for the sheer pleasure of having a more reactive foil.
It is nice, especially with older, slower wings like the Curve or the Rise, but with the newer faster wings, the other stabs make a *lot* of sense for kiting, at least in the smaller versions (so, wishing l'Ours comes out with a "S" Fluid stab)
Hope to have tempted you enough!
P.S.
I confess to have tried the Veloce XL + Veloce 43 once!
Weird feeling: ultra stable, ridiculous stall speed (5 knots with my GPS watch), but oh-so-tough to turn: it calls for wider arcs. Perhaps the Veloce 39 would have helped, who knows.
Also, an acquaintance kitefoiled with the Fluid XL-S + Fluid 43, at 70Kgs. He could perform all the usual manouvers, just noted that it was not a quick or reactive setup.
But I suspect, still much more lively than the Veloce XL.
There's definitely too much to be tempted from