From what I've read the gameplay doesn't live up to the story. I'll still play this because the questioning aspect seems incredible but these details seem to be troublesome:
1) looking for clues seems to be basically an easter egg hunt. You walk around the crime scene and when you get near a clue your controller vibrates. This doesn't seem to be so bad but if looking for clues is a huge part of the game that lasts about 20 hours.... well it might get old.
2) Chasing suspects. I guess occasionally you chase them on foot or get into a gunfight. The gunfights always end w/ the criminal dead. No option to get them to surrender or take them out w/o killing them. Foot chases look amazing but the game handles all the jumping, climbing, etc. All you have to do point your guy in the right direction.
Not enough to make the game suck...but two blemishes IMHO for sure. I'll still play this and love it once I get ps3