Question for tube aficionados

Objective evaluation of improvements in a stereo system is hard to arrive at.  There are so many subjective factors involved.  So I pulled out the Chesky “Ultimate Demonstration” disc that I had listened to prior to tube and amplifier changes. This is a very demanding disc which revealed severe limitations in my old system in just about every area.
Listening to it again now, I found the system to pass most of the tests very well. Of course, you could say there’s at least some degree of subjectivity involved here, too.  But, at least it’s somewhat objective.

RV, I was really lost about the Belles ,my 150a Reference VII has no problem driving my 4ohm , 87db Totem Sig Ones which are hard  to drive .
Knew nothing about the DQ 20's . Worked internet , 4-5 reviews all noted how hard it is to drive, several said hardest speaker to drive they had ever encountered .
One said 250 watts a side was bare minimum , 400 would be better, guessed its to be a 82db load .

At the risk of being a homey .The BelCanto 600M's are only class D I would consider .
durk. Most Bugle Boys sold are fake .

It seems that the Telefunkens and Amperex are different enough so as to require an either/or choice. Some have said that the Telefunkens and Amperex are no better than new tubes like the psvanes... has anyone compared all three side by side?