I keep hearing gossip that Savannahs with slats removed are having greater risk at heavy loads. I've done expensive testing years ago on this subject, and investigated several incidents. The results of all that work can be studied at http://www.stolspeed.com/flight-testing-slats-vs-vgs
Later Savannah owners maybe haven't studied this data, but everyone should. Yes, there is a risk in STOL aircraft such as Savannah and Zenith 701, from flyers trying to drag them off the ground at unsafe slow speeds. This is particularly risky with full flaps, as is analysed in the above article. The slower the aircraft lifts off the more the risk, so the Original wing with VGs could be slightly more prone that the 'VG' wing because it can lift-off a couple of knots slower, and of course the model with slats is considerably more so. This not a fault of the configuration of the aircraft, but the technique involved. My Savannah flight manual states, "...For Short Take-Off - full flaps, brakes on, full throttle, stick all the way back...." With this technique the Savannah will immediately rotate and lift-off, with less air speed than is required for the control surfaces to have enough authority. The tremendous torque of that 100hp at full bore causes a torque roll to the left. The flaperons are already at 40 degrees and providing heaps of lift. If the pilot tries to counter that torque roll with stick to the right, then the left flaperon could stall and cause that wing to drop even more, then the instinct is more stick to the right and the wing drops even faster and the drag that side causes the aircraft to yaw to the left and that wing stalls completely and it's all over so close to the ground. I know this to have been the scenario several times..... Not the fault of the wing, but rather technique.
Savannah and 701 flyers, please read and study and heed the lessons from that detailed analysis.
JG