No its awesome, reason people 'dislike' it is because, compared to the 1st game it doesn't add much. What people forget is that the 1st game was near perfect and more of the same honestly doesn't hurt at all.
I'd say its the best shooter so far of 08
I'd say play a few singleplayer maps to get the hang of how the game plays then go online. If you played other cover based shooters you won't have much problem adapting. What you should find out however before going online is which of the weapons you prefer, I'm pretty horrible myself with anything other than the SCAR CQC.