HI Allan,
Not speaking for Randy, but they are all reduced in size, so to speak, from the originals. SV-11, Tempest , Dreadnought, and Vector were larger versions that came first. Just a bit of added information. All are *SV* aero packages, I understand.
The SV 11 was my first serious stunt plane, and it was a great flier. I should build another!
Bill