SP campaign is to short, a few hour. In this part it is an average shooter like for example Medal of Honor.
But MP is to me a one of the best game ever. Only Battlefield Bad Company 2 is approximately good to BF3.
The game is quite demanding hardware but will provide viewing pleasure.
On average I play 2 hours a day in last 1 month.
The beggining was hard. But when a player unlock better weapons and when get to know the game, playing became more enjoyable.
Selection of weapons and techniques is huge. Sound in game are grate. Has and large variety of different maps like as an urban fight or open space in nature. If that's not enough, players can buy a new DLC with new maps.