RE: !/2 A APC props for pylon
You'll get lapped around here if you aren't running about 90 seconds on the 300 foot, 2 pole course. Local rules for engines and planes come into play, our planes are AMA rule book with stock TDs or AMEs.
The only leeway you get around here is prop choice.
The prop that APC specifically calls 1/2A pylon is a 4.5x4....but you have to be a good pilot to keep the plane locked in the groove or else this much prop load doesn't re-accelerate well.
The most important thing is to practice and practice some more. Even just an hour or 2 per week really makes a difference.