Are Quicksilver power tube amps in the same league as VAC, VTL, BAT, ARC, ...?

Warning; I own both a complex tubed amp-an ARC Ref 150 SE-and a fundamentally hair shirt simple amp-an Ampsandsound Nautilus SET. 
With that out of the way you may wonder why I consider my intro a warning. My answer would be that I have my biases. 
Take a look at the inside of an ARC Ref 150 SE 
 https://mans.io/item/audio-research/reference-150-se
Now take a look at the circuit of the A&S Nautilus
https://www.google.com/search?q=ampsandsound+nautilus&tbm=isch&hl=en&rlz=1C5CHFA_enUS872...
Quicksilver amps are much more akin to the latter. Sure they are push-pull and implement some negative feedback but they stick to fundamentals of tube amp design. So what at the end of the day does all this mean? Imho it means greater reliability, more midrange purity, less definition and leading edge transient snap/punch, and overall a softer more relaxed sound. The ARC build-a-beast-approach with 26+ banked capacitors and complex circuitry-for a tubed amp-helps explain why all said and done it does not sound all that different from a good SS amp though it does have the advantage of serving up to the loudspeaker a current based input rather than voltage based. 
The lower parts count and simplicity-not to mention lower overhead, advertising and mark-up, all allow Quickies to be much more reasonably priced. 
Are they the same at a miraculously low price? No. Are they a wise choice so long as you like the approach and sound signature? Hell yes. 

The Quicksilver amps look relatively easy to upgrade, e.g. better caps, being wired point-to-point and more classic than exotic; anyone doing that? 

The Quicksilver amps look relatively easy to upgrade, e.g. better caps, being wired point-to-point and more classic than exotic; anyone doing that? 

All I can say is that any designer that references RDH3 as the foundation stone for learning about tube circuitry knows what he is talking about.

WARNING -Do not Buy VTA amps if you have any issues with your line voltage, are they cheap-yes, do they sound ok-yes, I had nothing but constant issues with the VTA 120, I was told to make over 4 changes, none resolved the problems I was having, they are far from perfect, and there are many complaints about the electrical issues regarding the VTA 120 and 125s. I purchased the Quick Silver Monos, had them for over a year, they are perfect and can handle my voltage that can fluctuate over the 120s, no issues whatsoever.