I did a "new production" 6SN7 tube shootout several years ago. I used them in a preamp and DAC.
Here were my results
1. Shuguang Black Treasure CV-181 "Z"
2. Sophia Electric 6SN7
3. Shuguang Black Treasure CV-181 "T"
4. Shuguang Black Treasure CV-181 "TII"
There were several others, but nothing to write home about.
I found the "T" and "TII" to be too bright in my system. They did have more detail, but it reared it's ugly head as brightness.
Cryoing a tube is a HUGE waist of money. I have several pairs of different tubes that one set has been cryoed and the other not. There is absolutely NO difference in sound. I have read that "maybe" if you cryo a tube, it will last longer. No real way to prove that.