I really dont think that the single player was that representative of the actual game. Supposedly a lot of the dialogue has been cut due to spoilers, the dangers of cutting and pasting missions from later in the game. And that 1 mission was short, which doesnt say much for the length of the game, but Bioware is good at one thing and thats story, if they ever make what could be called a great game in 5 years still this will be it.
I will say this, combat is much improved, guns sound better, and zipping around the battlefield as a vanguard in multiplayer is hella fun, I'd hate to be the other people on my team following in my wake, watching me tear through the enemy while they are forced to try to keep up. I'm considering not taking a SMG now as I just dont use it anyways, may consider a heavy pistol depending on the weight.
Edit: Turns out you can solo at least quite a bit of bronze if you get higher levels as vanguard, infiltrator also seems to be able to have a fair chance with their cloak. Silver and higher though I think you do need 3 or 4 and thats really how it should be. Multiplayer.