its pretty good, though you need to find apps that do something useful, a few of them feel like they are using it as a mouse replacement so dont really make good use of it, others forget the fact that keeping your hands in the air is tiresome.
for me Geco is cool, to control software and hardware synths ( anything using midi cc).
better touch tool (for OS integration) looks like it it could be a winner, as its an exisiting product thats been extended for gesture control.
of course google earth is a laugh too :)
generally leap takes a bit of getting used to, in particular realising fingers get hidden if not seen by sensor but the supplied visualiser is good for familiarisation.
enjoy , preferably with beer :)