I honestly find myself switching all over the place. Sometimes SE, sometimes PP, sometimes high feedback, sometimes (but less often) none. SE is surprisingly robust too. Even with only 11W in SE, it has big round satisfying bass, so it doesn't need to be cranked up to feel good. And that "lit from within" 300B thing is definitely happening, it's a special sound.
Tone is accurate and very enticing and exciting. SE is a little less sizzle, but the SE midrange offers other joys. It is not too syrupy, but with other tubes that came with it like stock SED and Sophias, it was a little too sweet for me. It has VT229s and RCA6SN7GTAs for signal tubes.
I was surprised to find it is actually even more revealling of my upstream components than the Snappers were. The class A smoothness is addictive and makes jitter or bad caps really stand out.
I can put it into PP with 10dB feedback and play symphonic and even rock at decent levels without falling apart. But it will not blow down the walls like the DNA500 could. Not with these speakers anyway. But it's perfect for how I listen.
I still have the Zeroformers, so I was gonna experiment with those, but with the tubes breaking in it seems like there really is enough power without any help. I'll try them at some point.