How long do their batteries hold out? (I'm assuming batteries because "dropped from the air".) If they're "much" more powerful (than the quoted 3-4W) then I'd have some serious doubts that they're useful for much more than a short period of time. That said, I can think of operational scenarios where denying your enemy/target radio/GSM access for even an hour might be useful. Still interested to know the operating time, though...

I don't know the details and they are probably classified anyway. I know about the jammers from a person I worked with as a CS student. This was a project on improving frequency assignment algorithms in battlefield radio networks. We (the university) did the algorithms and they (military) did the reality checks on why a theoretically good assignment doesn't work in reality.

The military has phased array radar on airplanes that can wipe out communications over a gigantic swath of spectrum.