It was a challenge, aeronautically and physically, but neither Blyth nor Pittman worried excessively about their heavily-loaded Sling (carrying more than 700 pounds in fuel alone!). They knew it would do the job and they proved their claim in a dramatic fashion. Now, as they say, "You can fly the adventure!"
Maybe the best news about Sling's flight characteristics is that they are not in the least adventurous. The bird may have transported the South Africans around the planet but I found the design to have excellent control harmony (as good as the best I've flown), gentle stalls with ample warning, and great ease of landing.
When you lower flaps no big pitch movement occurs though slips also worked well to get to the runway at the target point. Stability throughout the normal range of maneuvers I explored was entirely predictable.
You won't find too many in the USA for demo flying in 2012 but two thoughts on that: (1) It's well worth a trip to where ever you'll find a Sling to take a flight; and, (2) the scarcity of Slings won't last long given agreeable pricing and wonderful airborne qualities.
To become a Sling owner, better you act sooner than later as I predict growing sales for the boys of The Airplane Factory.