Hey David,
I have flown the APC 20.5 x 14 and 21 x 15 and compared them to a RASA clone. I am still early in my learning so I can't speak well to performance except to say I noticed no difference between the performance of the APC and the RASA, but I can say the RASAs were quieter, 30g lighter, and way more cool looking
For one who is ever weight conscious the weight reduction was worth every penny.
Joe