Hi there Lou,
It's Mike from GCBM R/C (aka glowplugboy). We met in Paris. Me and the GCRC boys fly alot of Magnums and OS's, but I must admit none of us have achieved those figures on so little nitro. My Magnum .15's tach 17,300 on YS 20/20, and around 17,800 on 30% Heli. I wish ours COULD run at the SSC limit on less nitro.
Now regarding the Fox. What is interesting about the little Fox is how it seems to unload in the air.... definitely stronger than any of my Magnums. The plane is clearly flying faster than with my Magnums as well. Launch rpm is around 17,300, but at speed the prop tips sound close to going super sonic. You note I said 'close". A couple of good "dirt naps" will really tell the tale on the Fox, that is, see how it does after a few sub terra firma experiences. Only time will tell regarding durability and long term performance.
Regards,
Mike

www.gcbmrc.com