So I gave in and bought a quad of Psvanes EL34PHs, I’m impressed so far, I can tell a clear difference (better) than the JJs I was using.
The quality of the tubes looks good to my untrained eye, although when installing them I did notice that two had a slight rattle when shook (gently), felt like the filament was loose or something, is this normal an expected trait for an EL34? From memory some 300Bs had a similar trait.