He looks very good, and I'll definitely be getting him. Having said that, I can certainly pick a few nits.
First off, that cannon just looks a little weird. I think it's mostly due to how short the center segment is. On the MP, that segment runs the length of his forearm, and it runs most of the forearm on versions like Earthrise. Here, it's really short and shifted toward the front of his cannon. It makes it look like the front end is really short and the back end is too long. But looking at the comparison pic with MP Megatron, the cannon is basically the same length proportionally, and roughly positioned the same relative to his arm. It's just oddly proportioned amongst the segments. Likewise, the back end looks like it doesn't really flare out. It does, just the wonky proportions make it feel like it doesn't. I'm sure it's a concession to working in the turret, but Siege/Earthrise pulled that off better.
Second, he's too tall. In principle, I'm good with him being a bit taller than Optimus. Being visibly bigger than Galvatron though is something I really dislike. I can't believe this got me to order the DNA Galvatron kit for hugging leg extensions of all things.
At least I'll finally get a good G1-toy gun for him.
Finally, while he looks great in a lot of the pictures, he just looks kinda off from certain angles. I'm not going to read too much into it. Reminds me of how Kingdom Galvatron looked horrible in all his initial pictures. Hopefully, he will similarly look better in person than on screen. Considering how great he looks in most of the shots, that would make him pretty fantastic in person.
All in all, I like him. I'm going to be getting him. I really hope we get a G2 retool with an actual G2 tank-front chest and a translucent purple version to go with the GS Behold Galvatron. But having said all that, I don't think he's going to be replacing Siege/ER/DC Megatron for me. I think they'll still have a place in my main Generations lineup along with ER Optimus. SS86 is kinda forming its own little separately-scaled collection, which is kinda what I was afraid would happen back when SS86 Optimus was first revealed.
Final thought: This is the final nail in the coffin for me in terms of a Kingdom redeco being acceptable for an SS86 Rodimus. He'd be positively dwarfed when placed alongside SS86 Optimus, Megatron, and Galvatron.
