A few days ago my Gamerscore broke the 20K barrier. I was on 19995 and the achievement that got me past the barrier was Bird on the Ground. A Call of Duty 4 achievement which is achieved by shooting down an enemy helicopterwith an RPG in the single player campaign. Suddenly, however, 30K seems a long way off :(.
I borrowed Army of Two off Ben and I can say that the game is enjoyable. However, The AI can be frustrating at times. For example, when I die, my partner (who is controlled by the AI) will find it difficult to revive me or get to a good spot to revive me when I could do it easily if it was him dying. But, as annoying as this is, the AI does a good job at killing the enemies and spreads the killing out evenly. It's a fun game and I'm up to Mission 3 after about 3 hours.