While I haven't played the beta myself, after seeing a lot of beta footage I think they should do a rework of the current drone system.
They should make the two easiest difficulties keep the current drone behavior, but change ghost to this:
1) Actually realistic detection range for enemies spotting/hearing the drone. I get that it has black tech ultra stealthy rotors, but that thing is pretty massive in size.
2) Lets say, theoretically, that your drone self destructs (falls apart, basically) into various parts that look like bits of garbage to the average guard when it runs out of battery in mid-air. It makes sense that we wouldn't want this secret tech to get into enemy hands, charged battery or not. However, if one flies it back to your operator, then it doesn't and the drone cooldown function is called as your drone recharges in your backpack. Why would players make the effort to fly it back? Because I would call on them to implement drones like ammo; you get a limited amount per resupply and only at safehouse locations (where the CIA has access to secure caches). The higher the difficulty, the less drones you get per resupply. (On ghost, you get one with a new skill point upgrade that can give you two or more depending on how the devs want to balance it, for example). This would mesh well with the specialty drones, like the exploding ones, because it means you aren't carrying a backpack full of 50 exploding drones.You would have to carefully choose what to blow up or emp on each mission.