I think the english-language marketing 'spoiled' the game; the whole first part is about arresting Amada for breaking the law, while we all know already that the robots will Go Crazy and Take Over.

I have to say that without knowing how flexibel the story is, I really like the writing and characterisation. Its a good mix of pathos and humour, and it has that sense that Gears had of guys who knew each other and who talked shit while trusting each other.
Little Japanese kids making fun of Vendetta was a lol. :V
And I'll certainly keep this game until next week, but who knows after that. I can't trade it in for Synidcate because it's banned here, and it was half price, so I might. I still have Gears 3 but you might have noticed it sucks. :V
Regarding guns, everyone has their 'primary' gun you can't change. You guy buy other nades or pistols to replace the one you have, and carry a secondary. In single player it's arguably because your rifle has the magic boson shot, and in horde mode you can configure your guy however you want.
The highpoint of the game for me is being shown - not told - that Cain doesn't use a pistol because we can't trust robot with real guns. He uses a pistol because he is totally awesome and basically robot batman.