I have not been into this game for too long, but I am converted from MW3.
Daniel is right, the tower collapses at a certain point level, depending on game type.
The aiming and sensitivity are completely different, and I would describe it as more organic.
The feeling in CoD is more 'on rails' if you like, where the gun is held by your character a lot more firmly when swung left to right, and there is some sway in BF that just takes all your confidence when you first start to play.
Don't worry, it will come back, as you adjust to the play style.
You change guns all the time, depending on the game mode, and which side you start on.
The Russian side uses different weapons to the US side, which means you have two sets of weapon trees to unlock, if you like.
Jets are available wherever it makes sense to have them.
If the map is too small (ie: still massive) then you will be restricted to mobile armour, or your feet for getting around. Only when it can be a significant game changer, do you find jets sitting about on runways, just waiting for you to die in them.
The thing I would say is that initially, there is a lot to take in, there is a lot more to understand, and there is a LOT MORE going on than in a game of CoD, but once you don't let it all overwhelm you, and you get it, you will find it makes the game that much more alluring.
Try selecting Rush and then the map Damavand Peak. If you start on the Attacking side, and your team manages to destroy the first two bases, you will have to base jump down to the third, and that is a standout moment for a MP game, as far as I'm concerned......
MOST important thing to do is add friends, and play with other people.
BF is lonely, hard and frustrating if you are on your own all the time. The game really starts to shine when there are others giving you ammo when you run out and more importantly, bringing you back to life just after you threw your pad across the room for the umpteenth time, thus giving you the chance to grab that pad, re-sight that git who shot you, and take sweet vengeance.......

👍