well if you are talking about the little jet which I think you are, I have no problem using about 30% after initial climb to use this in battle. I've scored a few kills, but it's mostly just a change of pace fun plane to piddle with, and ensure you are going to escape for the most part.
Not sure why others are saying it's on or off, I have no problems with throttle management on this plane, and if I turn it down to 0% it slows down much faster than 30% so there is definitely a difference.