The BEST is difficult to qualify. All of those mentioned are noteworthy, but don't forget the Audiostatics. Their only real competition is from Soundlab. Too bad they're not more readily available here in the US.
Best Electrostatic loudspeaker?
Many of us have found that nothing make the magic happen like a pair of Electrostatics. It's been an evolutionary road for me, starting with various dynamic systems, then ribbon/dynamic hybrids, then full range planar magnetics (Maggies), then Electrostatics. So those of you with experience in Electrostatics, which do you think is (are) the best designed and executed example(s) of the breed?