Well he has good footwork defensively, he tested well athletically but he has trouble using it. He's a good scorer and he has a lot of upside.
But the thing is that Gordon is WAY better defensively and always will be. He's extremely athletic and knows how to use it. He's not a very good shooter but with a good shooting coach he can get better just like Kawaii did. He has a lot of upside as well.
Another thing to note, I notice in interviews that Vonleh seems really mellow and nonchalant and that makes me think he doesn't care ad much as he should. Not saying that he doesn't care but will he actually develop his game to the best of his ability? I don't see that happening.
With Gordon, like this guy said at my work, he's a winner. Seriously, Gordon is gonna go in everyday hungry wanting to improve his game. This is really the guy the Jazz need to take. No questions asked.