I owned quad ESL-57 and then stacked ESL-57 40 years ago. Loved them. WIth the right tube amplification and absent deep bass cravings, that is a compelling combination that spoils you for many modern alternatives, within SPL and dynamic limits.
I got into Zu 18 years ago after a multi-decades search for something that would deliver the immediacy of Quad ESL, crossoverless lack of choke points, and with the dynamic shove of an efficient dynamic speaker. From 1980 to 2004 that wasn't available, so I settled on reasonably-efficient 2-way systems. I also ran those Quad ESLs on a precursor to Atmasphere -- Julius Futterman hand-built OTL monoblocks, so we're roughly on the same page if time is offset by many years.
I have listened to many Devore-based systems. The central problem with Devore is poor integration of the behaviors between drivers. Particularly, the woofer behaviors are laggard, so in every Devore speaker I've heard, one hears disparate driver behaviors accentuated by bloated bass that just throws off any chance of coherency. I hear the crossover choke points over unified tone and time/dynamic behaviors, and the differences in tweeter and midrange dynamic behoaviors.
The Marantz 8b can sound old school and slow with certain tubes. If you are aiming for that quick, articulate, acrobatic Quad ESL sound from that amp with a dynamic (Zu) speaker, stuff it with the STR-450 EL34 tube Mesa Boogie sells (NOS last production Siemens/Germany). They are hypertested, reliable, crisp, clean, fast and toneful.
Once you do that, amp attributes accrue to Zu speakers. If you can't do Druid 6, Soul 6 is Zu's most lightning-quick, agile, acrobatic, responsive.speaker, and when you get the Griewe floor Gap adjusted, it's good for easily recognizable 32 Hz tones with an expansive, point-source dispersive soundstage
Point is, if you appreciate the agility of stacked vintage Quad ESL-57s, Soul 6 or Druid 6, or for that matter any Zu speaker is the closest dynamic equivalent for practical use in domestic spaces, and it will blow away the Quad on dynamic elasticity, tonal realism and convincing bass.