Down thrust can can really improve the flight handling of high wing flat bottom trainer type aircraft. I added what I thought was too much to a Top Flite Schoolmaster which was a small trainer type as I just described. The plane was the best flying of it’s type I had ever flown. It flew inverted as well as upright which is very unusual for that style of plane, furthermore, power changes did not affect pitch trim to a large degree as is normal for trainer type aircraft. It was a refreshingly neutral flying airplane, capable of good speed, sport aerobatics and yet still retained all of the easy slow flying and slow landing traits common to trainers.