Who ever used ELECDOL 12ax7?

They declare adopt strict selection criteria, provide accurate test results, and even provide test curve.

But I can't find any reviews of this brand on the Internet.
This is a new brand?

6SN7 & 12SN7. any of you guys who build or tinker have any opinions?

I know the au,at & 6sn7 are lower gain than their counterparts.

Any thoughts on the way they sound?

Thanks