i have both the Nexus and the Captain Cardboard X Wings and I have to say both are good kits but the Nexus is so well engineered so I'd go for that one. I believe Rodolfo is in the middle of moving so give him some time and he'll come back to you.
My V4 is still in production, but production has been pretty slow. I have a number of projects both here and in other places that have kept me busier than i ever expected to be. Again that is why i have only been taking funds for the kit as they become available (meaning i have some cast up).
Hammer i have a solution to the sagging issue. I am disappointed that happened. I called the supplier of the resin and i am trying to figure out what happened. The resin is supposed to have a heat deflection of 110 degrees Fahrenheit before warping. Looks like in the open position it will need a solid armature plug to keep the wings from creeping. We should be able to get your wings back in shape by plugging in the parts that i am going to fabricate.
Every version has had some sort of improvement. The V4 at this point has had the fuselage sculpt changed to more closely match the Pyro fuselage as the ref provided by Frank, as well as a change in the canopy frame. Also, the addition of the resin hybrid armature. Otherwise it's close to the V3
The biggest change was from the V2 to the V3, the V2 was the Captain Cardboard version (which i purchased the pattern for from Scott) with an improved fuselage and some added details. The V3 fuselage was built by Moe (all new) and i completed the rest of the ship, almost all new. The V3 wings are based off the pyro castings, I picked the slightly larger, thicker wing. The pryro had one thin wing and one thick, i picked the thicker wing for better stability. The V3 had new laser cannons, new phantom engines, new R2 strip etc etc....
The V4 is still a "generic" x wing in the sense that it does not match any one x, with the real things having slight differences among them. However i do provide the appropriate combo of the engines etc.