That the official FBX converter cannot read the trueSpace Collada is a shame really ...

Well, there is already X in two flavours onboard. But the new X from Workspace works with a DeclData block for the texture vertices. Haven't found a single app that can read this newest X derivate so far (Well UU3D can). They all fail to read the UV's. And from the old core you have the old X. But there is no way to transfer the new skeleton over so that you could export from there. And so this Modeler X is just good for static stuff really.

I use trueSpace together with Ultimate Unwrap 3D though, and have my working art pipeline. Collada - FBX - MDL.

trueSpace is still in transition from the old architecture to the new architecture. So no wonder there is the one or another bit missing. Not talking about the bugs. That's where the call for external plugin developers come from. Team is busy with the core features, so no time left for other things like other importers/exporters. I really hope they finish that one day ...