Iain- Serpent looks great and will be popular for sure, as size is perfect, we need more bigger, affordable sport jets...
Also Iain! I have done a lower inverted pass! unfortunately on my lowest pass the fin got in the way of said pass being even lower, the end result was spectacular! model sheared vertical fin off then climbed vertically rolling until I closed throttle and then gravity took over SPLAT!.... Luckily it was not an expensive jet, just a very old sport prop model....the gathered Sunday club crowd were mightily appreciative of the entertainment though : )

Cheers-