I've looked at these, and am intrigued by them. The issue is cost. At the asking price, you can still get superb NOS 6SN7's, and you can get really good 6SN7s for less. It is hard to justify running the experiment. The same goes for the Psvane globes. Judging by the lack of response to your post, it looks like there aren't many who are inclined to take a chance. 6SN7s are widely used. If no one on AG has tried these tubes, I think Sophia might want to rethink their pricing.