G'day Malc
Just came across your post... not sure why no one replied sooner, and basically took nearly two months for one reply.
Anyway, can definitely relate to this, apart from Maggie's, Apogee's and ML stats, I've also owned several Quad ESL's.
At the time the ESL 63's were hoisted on Gradient subs, one for each channel. I had Conrad johnson amplifiers (PV12 with a Premier 11xs in Triode mode fitted with EL34's) rated at just 35w it was quite good driving those Quads. However, after about a year or so, I sold off the Gradients and just ran the ESL 63's as is, and found a much more coherent sound with clearer definition and fine inner detail. Although LF heft was lacking, the music was still very enjoyable. Quads ESL's always had an enveloping affect to its sound, mainly due to its unique dispersion pattern.
After the ESL 63's, I ventured to the 989 then 2805's, 2905's and 2912's. There were a few years absence of Quads and this is where Maggie's and Apogee's came in, along with few ML stats (SL3, and CLSIIz's).
As the years passed (few decades...) I realised that Quads had quite a number of flaws, although musicality was superb! This is where I found ML stats to be superior in all angles! Not just dynamics, power, presentation and so on but also the soundstage depth and fantastic coherency between built-in subs and the stat panels. Several versions were owned: Ethos, Montis, Summit and now CLX's.
I've used many makes of tube gear (ARC, VTL, Manley Labs, Golden Tube, Melos, Quad and CJ), at the end of the day, I've always preferred the CJ tube gear. Especially with ML full range stats, there's no other system I'd rather own, regardless of price.
The Summits will open a whole other horizon of sound that you'll have the pleasure of experiencing. In addition to that, as already mentioned in the earlier reply, the Summit-X takes that horizon to another level! They are superb hybrid stats. If you get the opportunity to audition either of these Summit hybrid stats, you'll understand what I'm referring to straight away.
The VTL tube gear will work fine, and on hybrids that's plenty of power due to built-in bass amplification. Having said that, these hybrid stats can handle far more power than most would think, and when a more powerful amplifier is used with that added current and highly stable voltages, these stats really open up! It's a marvellous thing!
Cheers, and hope all goes well.
Woof! RJ