I'd drop the Buzzsaws on the Deffkoptas too, you don't want Initiative 2 models in at tiny unit sizes in combat, not usually anyway.
It could be worth to keep a few buzzsaws, for those times you manage a first turn assault against a vehicle (say, the enemy artillery), but it's pretty much an opportunity cost. I've managed to pull it off a total of two or three times, and I've played I don't remember how many games with orks.
Remember, rokkit'koptas hunt vehicles, nothing else. Then, the saw might be useful for a mercykill when the shooting goes worse than usual and it has to be neutralized for the next turn.
GENERATION 15: The first time you see this, copy it into your sig and add 1 to the generation. social experiment.