A Lectron isn't really any more efficient than a Mikuni or Keihin, but that's not what makes them better.
The ability to fine tune the top end is what makes them so much better than the others.
That powerjet can easily tune the top end to a point that's between main jet sizes, which can mean a big difference in HP if tuned to the ragged edge.
The other nice thing is that if you think it might be running a little lean during a ride, you can always reach down and give it a little more fuel to keep it safe.