Overall, I'm just kinda split on Nexus right now. I've been expecting him to be a combiner torso since we first learned he'd be a Voyager. It really seemed like the only thing that would make sense for him to be any sort of combiner at a Voyager price. No, I've never believed that we would get any sort of self-contained combiner at a Voyager price that would manage to be even half as satisfying (however much or little that may be) as this is. It just never seemed at all realistic.
I'm also not at all hung up on the idea that he must be the combined mode. That's how he was conceived per both the Binder and Covenant, and that's how he was depicted in his first fiction. However, he seemed to be just a normal bot in IDW and One. So the idea that he'd split the difference here, being styled after One as a normal bot who can combine with others into a form more styled after the FunPub and CoP designs? Sure, I can appreciate that.
I can also appreciate some of what they're going for on a purely toy level. Turning the torso around to make Nexus be the chest plate? I'm sure I considered that at some point, but somehow convinced myself that wasn't feasible for some reason. Clearly, I was wrong. The result is not exactly spectacular, but it nicely eliminates the issue of the combined mode just being Bruticus or Superion with Nexus's head. And I can live with Nexus being a bit primitive as a combiner, being the first and all. If they worked it out so he can also use the Menasor frame, that's something I'll honestly really appreciate. And with the line's theme of focusing on all the Primes' artifacts, having the Enigma be something he uses to combine with other random bots feels like a better fit than having it be something he uses to let other bots match up to him.
However, the frame combiner system is really showing its limitations here. He really deserves to have a full set of combining buddies of his own. But how are they going to manage that now? If they were to go the FunPub homage route, he'd need to use Brawl, Vortex, one of the Aerialbot arms, and one of the Aerialbot legs. On the arm side, no issues, aside from having to swap Brawl and Vortex from FunPub Nexus's nominal configuration. Superion's and Bruticus's arms are fully interchangeable. But on the legs? Brawl is front-mounted, while the Aerialbots are rear-mounted. They aren't compatible with each other. So doing a full FunPub homage is going to be tricky without doing a full new frame mold, since neither Bruticus nor Superion will work off the shelf. And since I doubt either Onslaught's trailer or Silverbolt's... aft section will work with Nexus, getting a new frame just for Nexus is probably the most realistic option available, even as unlikely as that is.
So yeah, conceptually, I'm pretty OK with everything they've chosen to do here. In practice, I'm not thrilled, but mostly OK with how this individual bot turned out. But in terms of getting the full Nexus Prime combiner I really want? This is coming up way short, and I'm going to need a lot of convincing to have this not ultimately end up being a disappointment.