I like to holster, because I dont want to risk my special weapon glitching trough the ground or some random dude picking it up.
Also here are the times
Holster: 60 seconds
Dropping: 30 seconds
So dropping gives a lot of an advantage in time, but there are greater risks than holstering. I always use my special weapons like this:
- Hide in a place on the map nearby or in a car end equip the special weapon
- Start holstering your special weapon
- Wait until the holstering timer reaches the last dot (could be earlier, but I prefer somewhere near those last dots)
- Shoot your special weapon and get back into the car/hiding place until your special weapon is holstered or go straight into the base you just blew up if your weapon is already holstered