I built my Storch using the Power Pack 'C', and she flies beautifully. I fly off a dirt runway, and take-off at around half throttle or so. She does a reasonable take-off roll, then lifts easily into the air. I've flown her twice now, and find her to be one of the easiest planes to land of any that I've flown.
So far, I've not flown her with the leading-edge slats, nor did I incorporate the optional flaps. Next flight, I might just advance her to full throttle in flight, and see what she does for "full speed."
Here's the video of her maiden. About the closest thing to any mishap, was I drifted off the side of the runway while landing. Otherwise, I was quite happy with that touch-down.