I purchased one of the first LeapMotion devices, and I was not terribly impressed with the performance and returned it. Not sure whether the IP has much value with Google's Soli [1] project seeming to be further ahead.
But it didn't improve enough to be useful for anything practical. The most useful thing I could make it do reliably was detect swiping your hand left and right. I was really hoping I could use it as a mouse replacement on laptops, but accurately tracking individual finger placement never materialized.