Regarding the differences in harrier between a Cap and a Yak. The 232 is the plane that all others have come to be judged by when it comes to a harrier. With the exception of a really big Yak I have not seen a plane to date that does it better. The Extras are pretty good at it, but generally perform the maneuver better if inverted. The position of the empennage in relation to the main wing is everything in a harrier. Many models pay close attention to the general appearance of the full scale plane, but miss the tail relationship completely. That will leave you with a plane that looks generally right, but is off the mark in performance. As noted in another post, weight and wing loading bear significantly in the final performance too.

On to props, my opinion is that an 8 pitch prop would be better. I'm one that believes that too many people are over propping the DA 50 and unknowingly suffering a loss in all around performance for doing so. It's a "well he's doing it so I'm going to do it" herd instinct type of thing. You may benefit with the greater pitch in one area, but suffer in many others because of it.