Not much
Personally I never flew a Hydeout or a Prophecy. Troy Newman has a great deal of experience with a number of these planes. He thinks that the Temptation and the Hydeaway fly very similar. My freinds built 2 of the ZN Hydeaways last year and they liked the Piedmont kit better. Plus the difference in cost is at least a few hundred dollars. The other plus is that Piedmont has stock. Ordering ZN Lines from Central is a problem in that they rarely stock them and you never know when your going to get them.
Mike