How much faster does an Anti Ship Drone Mark II fire than a Mark I?

1 Mark II is not quite as fast as a 2 Mark I drones. According to the fan wiki, the firing speed of a Mk I is 15, and a Mk II is a 28. OrigamiRobot's observation would hold there; 2 Mk I drones will produce more shots than a single Mk 2 over time. Though it may take a couple of volleys for that to bear out.

There are other considerations that might dictate usage. A Mk II costs the same to power as 2 Mk I drones, but the Mark II only takes up one drone slot, and some ships are limited to 2 drones.

I believe it takes ~ 2 seconds to recharge a point of shields, before crew skill ( worked/level 1/level 2: 10/19/29) and the shield recharge augmentation (15) comes into play.