Question for Engineerbros: Explosive Drone or Attack Drone?

[Nikolai]

It's my 5th playthrough of the series and I have never played an Engineer before! Given that the Drone is the Engineer's signature ability I've decided to max it first, but I'm torn about which version to commit to. I can see the wisdom in getting Attack Drone, given all the various resistances the enemies have, but having an explosive drone is rather tempting as well since they love grouping next to each other so much. Any input from Engineer veterans would be greatly appreciated!

[AbedsBrother]

I usually go Explosive, just because the drone usually winds up surrounded by enemies (& gets destroyed) anyway.