ESL57 vs ESL63

The 57’s are going for twice the price of 63’s.

i like the managable size of this speaker, this is really a part of my soon to be retirement built two channel system.

besides the price, how do these two fair amongst each other. Realistically how much power do the require, tubes ? Solidstate ?

my hope would be to also get into lower powered triode type amps with this projects.....

It seems that when properly set up and amped there is very little that can compare to the sound of the ESL 57’s - the realism, resolution and liquidity, just seems to be unmatched for all acoustic sounds (e.g. jazz, classical, country, sax, trumpet, violins, cellos, bass, guitars, voice, etc.).  But, I guess you have to be tolerant of their set up requirements, and prefer the kinds of music at which they excel.  Which is why I’m considering the WP ESL 57’s.  

But, are there any dynamic speakers that come close to duplicating their sound quality?

It seems to me, that the Harbeth 30.1 and 40.1 / 40.2, when driven by the right tube amps, come very, very close to duplicating the sound of the 57’s.  

Does anyone else think so? 
Sure, other ESLs. It is just that people do not get to hear them as the big ones take up a lot of space and are domineering. For some reason shops do not like keeping them around. Maybe hard to sell a Magico or Wilson with Soundlabs on the premises. It is hard to miss them and they are a much better value if you can get them by the wife. 57s were amazing loudspeakers 50 years ago for Brits who like classical music. But, technology moves on particularly materials science. There are ESLs made today and in the past that have the sound qualities of the 57 and are not nearly as temperamental.  
I run 57s (with grills off) on 20" stands with 1960s EICO push-pull tube amps and they can go pretty loud and sound magnificent. I’m not sure why but in my set-up they sound better than all speakers I’ve ever heard at shows (for what they do - the glorious mids) I wouldn’t swap them for anything... but I do run a second rig with cone speakers and sub for HT and digital. Because sometimes you just need that power! I tried the 57 with a REL sub and it wasn’t great so I removed it. I can’t really say how good they’d be in a sub-based HT situation but I wouldn’t do it. Do not mount the 57s on the subs directly. See systems.
Hey noromance, did you build those Eico's?
@mijostyn No. Stu Remmington rebuilds. Chokes, fixed bias, film bypass/PIO caps and triode input. 
I have another pair of recapped originals.