It's definitely different, but I have to say a lot of the changes are growing on me. The weapon switch being changed to the Y button really had me worried, but with the way it's set up now, I'm digging it. I like the new weapons, espescially the Breechshot. I also enjoy the "prize box" aspect they've incorporated to get more XP, skins, etc.
I have not dove into the campaign yet (waitin' on the missus), but so far I'm overall happy with the game.
That having been said, Overrun is a bitch if you aren't working with an organized team!