Vortec, sorry to see that pic.

I had the BH extra before, was running it with a TT46PRO, was a nice flier, but not really great on aerobatics. Then I tired the 12/25x3.75 prop. WOW!!!! Knife edge was a breeze, it just became a different plane altogether. Unfortunately I crashed mine some time back. If you do use the 12.25x3.75 prop, just remember that you have to hold the throttle open a little for landings as this is a slow speed prop. But the increase in thrust makes aerobatics so much more fun and easier.