The only time that the slats were any good were in tight turns pulling 'G', and one day they even saved my life and I am forever grateful for them. I was glider towing and coming in fast after a tow. The field was by a hill and the wind 'on the hill'. The approach thus was to turn in front of the hill to land into wind. I raked the tiger into a steep low turn by the hill to turn into wind and ran out of elevator, I was going to hit the hill. Then suddenly the slats popped out and gave me the extra elevator I needed to complete the turn. So now you know, yes they work!
Bob