I am a huge fan of Scanspeak, and that is who they have sourced their drivers from. They now use custom driver materials though. Also, I have toured their factory. They use the highest grade Mundorf crossovers. Or rather, they match the crossovers to the speakers. The top grade speakers get the top grade Mundorf parts. This is not something a lot of speaker makers do.
Sound Stage network just released the measurements for the S1 MK II. The crossover and frequency response measurements are really very good, and could only be achieved with very good parts, though compression figures were disappointing, especially in the treble.
Having said that, are they the best? That’s debatable. If I absolutely had to buy speakers and could not build my own, I’d probably want to hear Gryphon’s and anything with the latest Accuton cell drivers like the Marten Coltrane.
Having listened to Magico’s, B&W’s, Wilsons and Focal’s, among those brands I would rather listen to a Magico all day long, but not for $100k. :)
Best,
Erik