Jason,
as John said, sgx's crapshooter, roadrunner, tiapan are all good boats,
and have different theroies behind them on how and why they work,
i have run several diffenent boats over the years and built serveral of my own,
my opion rear sponson's are a must for heat racing,
as they help support the prop on launch,
help support the prop through the corners,
help stable the boat down when it becomes flighty.
and can help with down force at the rear[prop stay hooked up.
on my SAW 67\80 boat i added rear wings like sgx's for the down force at high speeds,
as i had a prop weight which was on the lighter side and at speeds of 100mph+ the prop
would brake loose, with the winglets this helped the prop stay hooked up.
the old saying there is more then 1 way to skin a cat,
great topic guy's keep it going
regards Aaron