Definitely not as good as the console games but its a solid debut for the franchise on the PSP.
In my opinion, i made the right choice. its a fun game when you dont have anything to do and you want to play a shooter on the PSP.
But the game has it's flaws. you definatly dont fell the sense of tactics that make the console games so kick ass. the game is played again from the point of Mitchell but the rest of the ghost squad is not present (except for one mission where you rescue them) they are implied to be out of action due to injuries so Mitchell flies solo in this story (its an original story that is different from the console GRAW 2 games so if you are unsure about the game fearing its a watered down hand-held version of the console games dont fret its different)
when it comes to weapons in the game, alot of the basics in the GRAW series are there like the M8. the story will get very frustrating if you dont have the OICW rifle with you. in most missions they want you to laser designate things to get air striked.
i think its a fun game. the graphics are good enough, it dosent have multiplayer, but it has game modes that can be played wirelessly with another player on AD HOC mode. and if no one is there to play those modes with you, you can play them solo as well so thats good.
all in all, not the best of the franchise but worth the money if things like graphical differences between the console game and the handheld game are big problems for you.