I have found that when I try to rip a groundstroke on the forehand side, it feels good to lift off the ground. But i also find that the ball goes hi and long when I do this. When I have experiemented and kept my feel planted firmly, i get a lot more control, but undecided on power. If the ball is higher it is ok to jump IMO, but on those waist height balls, lifting off the ground appears to be a recipe for disaster. What have you found???