Best Electrostatic ?!?!
Yes. The very best. Made by Sound Lab. Why is it the best? Its the one that plays the deepest bass and has the greatest dynamic range. That is why- otherwise, Quads, ML, etc. are all quite convincing (and excellent IMO) due to the speed of the diaphragm and their cohesive nature endemic to ESLs. But only one was conceived to be a full-scale loudspeaker, one that is ESL from top to bottom, one that you don't have to worry about putting more than 35 watts into it, etc- and you all know what I am talking about.
So Sound Lab is the best ESL made by nearly all standards. Not saying that that is the way it will always be, but so far I've not seen anyone else really take up the gauntlet like Sound Lab has.