Our car has the standard key for the UK market. It has four buttons and a metal key which slides out for emergency use if the battery dies. Three of the buttons are dedicated to lock, unlock and front locker/bonnet/hood release; the fourth has a diamond symbol on it and is allegedly programmable. The diamond marked one opens the tailgate on ours as it came, and I don't expect us to attempt to change that.
In practice you approach the car with the key, press to unlock driver's door, press again to unlock passenger door, get in, and from then on it's a proximity RFID key. BMW have moulded a little socket into the front cupholder where you can stow the key, or you can keep it about your person. It works fine and I'd not pay for anything more. You can also lock and unlock the car remotely with the BMW iPhone or Android app.