So you actually have not heard big difference between regular tubes and cryo ones.
Some AA owners claim that difference is huge after applying SE upgrade, but it may be VCAPs not tubes, who knows. Do I believe in cryo treatment, not yet, curious it will not hurt to try. I will have piece of mind
I have already ordered CuTF VCAPs, I like the way AA Cap mkII sounds in midrange, but I would like to have more resolution and speed.
I have asked Tube World about differences between Sylvanias and Raytheon but they would not comment. Since they are out off Sylvanias I guess they will not recommend them and will not criticize tubes they have in stock.