BF3 has larger maps and vehicles , sniper friendly... Spawn camp/flags... people will kill people in the spawn.. capture nodes, spawn on squad leaders... different classes
MW3 faster paced , cant snipe very well with an actual sniper rifle.. only so many spots to snipe and most people will know where the sniper is/might be.
Ill be getting BF3 for PS3, and probably get MW3 for CPU... pending because if my friends online wanna get BF3 I might not get it for ps3 since i got for both systems once... (bought a used copy, still Pricey)
With regard to sniping, I thought MW2 was very sniper friendly. Throw on a thermal scope and a 50 cal with stopping power and you were unstoppable. Easily my favorite weapon in MW2. BO gets a bad rap because there is no stopping power, but I really don't have any problem sniping. There are quite a few maps that work great for it, especially on the new map pack (Silo is GREAT for sniping). So I don't know that I would agree with that. I agree that the spots are pretty well known, but that's not a bad thing. It's kind of annoying when you have 10 snipers on the other team in BF and you CAN'T find them. If they are any good, it's impossible to get close and makes for a very boring match.
Very map dependent, pretty much everymap in BF2 you could snipe. Tho engineer who was good lonnnnnng distance with the Gustuv might get ya haha.
So yeah you can snipe but you wont be very useful in mw3 sniping. Unless they changed it, which I doubt they changed the gameplay that much, its a cash cow.
Thats the point to sniping... finding a new spot, keep moving so when they go to look for you, bang you get em again. Try delta force where you can snipe at 1000+ m's ... those were the good ol days... havent played one in a very long time... but loved it.
Mw3 is all about positioning, when you have a team that moves well together and keeps cutting off the other team before they can get settled they get rocked. gotta run around to do it, cant just sit in the ideal sniping spot. Unless of course your doing an objective where you are camping but then again you dont want a sniper in most cases... and most maps. You can snipe with an assault rifle and be better than a "sniper" just because the maps arent that big and still be effective close range.
Most of the time in BF2 if you were sniping you'd be looking for the other snipers first, and sometimes it was annoying when there were too many snipers! because your team wouldnt move forward bceause you got half the team as snipers in the back.