I prefer a Sonic that develops as is. It's that simple. I don't like bland characters that are the same forever. It's not interesting.
And yes, he's always been a simple heroic personality. With snark. That's unfortunately all he really is, outside of actual various interpretations that bother to change it up a bit. And he isn't even that complex either. Hell, his own point is that he's a simple person. He intentionally makes it sound that way. "I'm just a guy who loves speed."
I love the fact that other series bother to mold him into a personality, not just have him "be that". We never see his past, so it gets boring with the same personality over and over.
And yes, he's an ***, just with snark even higher than normal, in other interpretations. The key factor is he can slowly gain character development and personality traits, and has. He's never really gotten complex in his regular form. And I clearly see that as an issue. He's too simple. I don't care about the fact he was a foil to Mario. That stopped being relevant when he stopped being a pure rival to him for his "reason to exist". Sega's a third party development. It doesn't even close to matter anymore on that front. Sonic should be himself, and show real development for once. With all these games starring him and only him, you'd think basic character development would be part of it. But they didn't do anything useful with his characterization, just kept it the same. Even Amy(who is vastly more complex because they actually, you know, gave her some kind of development) showed some hidden depths, more than once, even. They developed her pretty early on in Adventure 1, and it was a great change in that game.
If you don't want Sonic to develop, that's fine. But I don't think it benefits him to be the same character with little differences beyond his new gameplay. After heavily developing every other main character, never mind having main characters who are more complex as well, they could at least bother to do so to the key character. It doesn't even need to be much anyway. Just something new to him. Like, all we've even close to gotten is that there's a possible chance he feels the same way about Amy... and that's just from Sonic X, anyway(which is his canon game personality), and that should seriously have slowly translated(although it was nice Unleashed kind of attempted to show that). It's still some development, but it's barely anything.
Anyway, it's obvious we see him in a different light. So there's no point in going back and forth. I think him starting as an *** leads to better characterization overall. You don't. No big deal either way.