Lookinup leaves great advise. Talk to the guys you will be flying with. I have both. Both companies make great engines and you will be happy with either as a first 4 stroke. What will be most important is how you setup/adjust and break in a 4 stroke. Rely on an experienced club member for this. Just remember that you do not tweek in a 4 stroke into a lean condition like a 2 stroke and they put out a bit of smoke. You may damage the motor with a lean condition and it is hard to adjust a 4 stroke by ear the first time.