Which one to choose between two 80K$ tube amps?

It also has better control of bass than 100 Watts Rogue Cronus Magnum II fitted with KT120 tubes.

Sorry to be so late to this thread, but I have owned several SET amps (and love them), and was smitten by the Robert Harley review of the Berning 211/845 monoblocks that I bought a pair.  Dang if they didn't just smoke my previous favorite amp (SET), not to mention the 4 other amplifiers in house.  I play them through a pair of Avantgarde Duo XD speakers, and the Berning monos have all the things I've come to love about SETs:  Crazy good dynamics, the timbre that says the artists are in the room, just right warmth, majesty when needed (Mahler) and intimacy when needed (piano trios).  They simply sound live.  Well, the Berning was the first amp to give me that plus have more power and an effortless-ness missed by the SETs in big passages, and WAY better than any solid state amp I've used, despite their power.  Anyway, there is a used pair out there for sale, FYI.

The sound of amplifiers is FAR more than the topology employed, the tubes running in the amp, the parts chosen, etc.  The designer voices their gear for a particular sound, and then there is the matter of how the gear plays with the rest of the system.  I have not heard this very upscale Berning amp, but I've heard many other amps of theirs.  I appreciate what they do very well--clarity, great dynamics, vivid sound, but for my personal taste, his gear sounds a bit too lean.  It is certainly NOT in the same camp as original Western Electric if that is what you are trying to achieve. 

Some of the highly sought after Western Electric amps, such as their 300B SET amp, their pushpull 300B amp have crossed the $100k boundary for a pair.  Their 252 amp has probably crossed $300k for a pair (these sound fantastic).  But, one can still find their 350B amps, like the model 124, or their 349 tube amp (model 133) for less than $100k.  Clones of the 124 amp using genuine Western Electric parts can achieve truly great sound.

A very interesting practice that is more common in Japan is using booster amps between the linestage and the power amp.  These booster amps typically have a 600 ohm output transformer.  The gain of the downstream amp has to be modified to work well with the booster, but, when this is done correctly, the sound is amazing--very vivid, the soundstage becomes very big, particularly front to back (the sound is enveloping), and dynamics is much improved.  When placed in the right system and done correctly, a booster amp does more than anything else I know of to improve the sound.  In particular, they seem to give a lot of kick to otherwise somewhat polite 300B amps.  I have heard BIG improvements with boosters as low priced as $6,000, but the best boosters I've heard were clones of Western Electric 133 amps that utilize genuine Western Electric 618 input transformers and 171C output transformers (pricey combination).  Use of booster amps was also a common practice of Western Electric and some of their best amplifiers had booster stages built into the amp itself (like the model 59 that runs the 252 tube).

The designer voices their gear for a particular sound

@larryi I hear audiophiles talk about this, but I've yet to come across a designer who actually does that. If they do, I would regard them as incompetent. As far as I know they don't; I certainly don't!

Most SETs are something called 'series fed' which is to say the output transformer is in series with the output tube and power supply. This arrangement causes a DC magnetic field to be present in the output transformer; if left to its own devices this would cause excessive distortion since the core of the output transformer would be saturated. 

So a gap is introduced to the core, which mostly eliminates the DC saturation problem thus eliminating the distortion it would otherwise cause, but it comes at a price. That price is the inductance (the property that makes any transformer work the way it does) is reduced at lower frequencies in the audio band. 

This is the 'bass problem' most SETs have. To combat this, most SETs have much larger output transformers than they would normally need for the power they make, in an effort to keep the inductance up. But there's a limit because larger output transformers can't do highs as well. The lack of inductance at lower frequencies causes the amp to make a lot of distortion (as essentially it clips at those frequencies) and also heats up the power tube unnecessarily (IOW its hard on the power tube). 

Western Electric solved this problem before WW2 by designing something called a 'parallel feed' circuit (often known as 'parafeed' as opposed to series fed). In this circuit the plate load of the power tube is a choke that won't allow audio frequencies through it. The audio is then passed through a coupling capacitor to the output transformer. Since it does not have to deal with DC current, that output transformer can be much smaller and yet will allow the amp to make full power at 20Hz, something most SETs have no prayer for.

Western Electric's new SET is a parafeed. 

Of course the Berning amplifier side steps this problem as well.