It sounds like fun doing this sort of listening shoot outs, but, I hope you don't draw broad conclusions from the results. At best, you can say this or that particular amp, running a particular set of tubes, in your particular system, and in accord with your particular taste, was the best. You will have just one set of data in the evaluation of particular approaches to tube amplification.
From my own experience, I would not conclude that one particular approach is the best. I own two pushpull amps--one using the 45 tube, the other 349 (i.e., both amps are low-powered), and I have owned and heard many other pushpull amps. I also own a parallel SET amp (2a3) and have heard many other SET amps, including those that run 211, 845 and other somewhat higher power tubes. Note that many of the cheaper amps out there running the 211 and 845 do not run them at the very high plate voltages that the tubes are capable of running (a good thing, given how dangerous this can be if not properly constructed). I have also heard about ten different output transformerless (OTL) amps. If I were forced to pick favorites, my top picks would be a custom made OTL amp and the pushpull Western Electric 59A amp (runs extremely rare 252 tube). Among the amps I own, I like the pushpull amp running 349 output tube (essentially a rebuilt Western Electric 133A amp) the most even though it is not nearly as expensive as the parallel SET amp.
At least as important as the basic topology is a whole host of other factors, such as the quality of the parts (particularly output transformers), the basic design choices, and tubes utilized in the amp. Like anyone else into the tube game, I have my favorites, although this does not necessarily mean that anything else is out of the game. For example, with respect to tube types in pushpull amps, I tend to like 6L6, KT66, EL34, and EL84 tubes over the likes of 6550, KT88, KT120 and KT150 tubes. For SET amps, I like 45 and 2A3 tubes over the popular 300B.
There are no outright winners and losers in ANY give aspect of tube amp designs.
From my own experience, I would not conclude that one particular approach is the best. I own two pushpull amps--one using the 45 tube, the other 349 (i.e., both amps are low-powered), and I have owned and heard many other pushpull amps. I also own a parallel SET amp (2a3) and have heard many other SET amps, including those that run 211, 845 and other somewhat higher power tubes. Note that many of the cheaper amps out there running the 211 and 845 do not run them at the very high plate voltages that the tubes are capable of running (a good thing, given how dangerous this can be if not properly constructed). I have also heard about ten different output transformerless (OTL) amps. If I were forced to pick favorites, my top picks would be a custom made OTL amp and the pushpull Western Electric 59A amp (runs extremely rare 252 tube). Among the amps I own, I like the pushpull amp running 349 output tube (essentially a rebuilt Western Electric 133A amp) the most even though it is not nearly as expensive as the parallel SET amp.
At least as important as the basic topology is a whole host of other factors, such as the quality of the parts (particularly output transformers), the basic design choices, and tubes utilized in the amp. Like anyone else into the tube game, I have my favorites, although this does not necessarily mean that anything else is out of the game. For example, with respect to tube types in pushpull amps, I tend to like 6L6, KT66, EL34, and EL84 tubes over the likes of 6550, KT88, KT120 and KT150 tubes. For SET amps, I like 45 and 2A3 tubes over the popular 300B.
There are no outright winners and losers in ANY give aspect of tube amp designs.