I think the primary reason you don't see many statics, is that they would be very difficult to do in fiberglass. When I say static recurve I'm talking about a good 45 degree bend at least... not just a stiff tip. It can be done with a wood bow of course, but fiberglass bows tend to be too thin in cross section to handle the stability issues of a lever on the end of the limb.
If I take my wooden static recurve that I built and try to twist the static part, it feels at least twice as stiff as my working recurve fiberglass bow. A working recurve glass bow will become more geometrically stable when the curve 'unfolds', otherwise the limb would want to flop to the left or right.
As for efficiency and speed... I'm not sure on that one. I've heard it both ways.