A lot of fun but it has its flaws
Pros:
1) You can customize your character and weapons and you unlock more weapons and armor for your character.
2) You can rank up in multiplayer as well as in campaign mode and if you level up in the campaign it also shows up in the multiplayer.
3) Great graphics even though they havent changed much from the first one.
4) The sound makes you cringe when you get a good shot.
5) The controls are sharp and will never fail you.
6) You can play split screen co op.
7) Very fun online mode.
8) It answers any unanswered questions from the first one and it continues the story well.
Cons:
1) Only 2 player co op online opposed to the 4 player co op in the first one.
2) Short campaign mode.
3) Controls are a little bit hard to get used to when you first play but ultimately work well.
4) Customization could be deeper.
5) Same music as the first one.