Actually, I'm leaning more towards pusher props and edf configurations. Lesser blade and motor/bent motor shaft replacements.
I have several mini-fms warbirds but none of the funfighters. I have a friend who have 3 of these funfighters namely the rarebear, the A1 and the AT-6 which he runs on 800mah 4S 45-90c nano-tech batteries. They are really fast! But now I mostly see him with his Skywalker doing fpv with the goggles and all the latest stuff.
Also, I love the sound created by these edf's and screaming pusher jets which the funfighter does not have.