I thought B3 was a shooter so why are you worried about vehicles? Go play GT5 or Forza 4 if you want vehicles. I'm after a good story shooter and MW 1,2,3 have that. B3 is a copy of BlackOps and BO was crap thats why I think B3 is crap. The gameplay is done poorly, the story is stolen and the AI is pathetic.
Example if bad AI in B3. When you the French dudes breaking into the condo place there is 1 part then your trapped at a corner and 2 guys shooting at you. Kill them then shoot the 1 guy in the other room.
If your quick enough you will see your guys run up the stairs in the next room and an enemy runs right past them. neither shoot each other, your guys just run past and the enemy wants to shoot you. Pathetic gameplay.
That kind of thing doesn't happen in MW3 thats why its better. For a shooter MW3 kicksass over B3. Want more examples of poor gameplay? I've finished it on the 360 and PS3 as its so small it only took me a day and its all on rails. try running ahead of one of your team members then hide behind something. If your in their spot you will be pushed out and probably shot because of POOR gameplay.
Again, pathetic. This is probably one reason people want MW3 to be cracked to play on the PS3 as B3 is just pathetic and people want a good game to play.