I recently upgraded to Psvane Acme from Shuguang Black Treasure in my custom built 300B monoblock amps. Acme in different league from Shuguang. Much higher resolving and far more natural timbre. Haven't tried any other premium 300b up to this point, but based on my research and observations of 300B's, I don't think you can go wrong on any of the boutique 300's. Slightly different flavors, all will resolve and have refinement you won't find in lower priced 300.
For me it was sort of like throwing darts, whatever came up winner I chose. If reliability paramount, EML XLS and WE only 300B's I''ve yet to see any failures with. The Acmes are really extremely nice tubes, aprox. 75 hours and getting better!