Actually I've found it works well against most ships, bar Rockmen and automated scouts. The AI doesn't have the power to vent the way you do, and the fire beam can easily start fires in 4 to 5 rooms, so they're usually still putting some out by the time it recharges. You don't even need to board to finish the job: if the ship has a substantial amount of hull it can usually tank the damage from every system burning down without exploding. I've found it to be the best non-boarding way of taking ships intact.
I say it's my 'favourite' way of dealing with the drone because it's much more vindictive than just shooting it down