Experimental version 1.2.0.52
No mods

Exiting a vehicle is very slow.

Press X, player slowly gets out of vehicle, glitches around for a second or two after exiting before becoming playable.

Double Tap X (I believe this is supposed to be eject), same.

Not a problem if you're not in a hurry but if you're under fire at the time you'll probably get shot before you ready your rifle.

Perhaps double tap X should mean "dive out of the vehicle straight into the prone position ASAP". Or at least get out quick and go to crouching position.