Its not mentioned. But I would think they excell at the role. During battle there is no way a capital ship can deploy personel to get rid of them, while the buzz droids can slowly cut thru weak points, or attack devices like turbo lasers.
On the other hand, against freighters seems to be its traditional role, which they do not excel at. I mean, things can be easier if they would just walk to a freighter's engine unit or cockpit, sick out a demolition charge, and boom goes a freighter. It is much more effective than what is shown on Ep III. Now, against things like transport and bombers they would do a much better job.