I have a pair of Psvane 12AT7's in my VAC amplifier. I don't know that I can really comment on how good they are though, because they replaced Telefunken 6211 tubes that came with my amp. While there was a much better tone with the Psvane 12AT7 tubes, I'm not sure if the difference is because the 6211 tube has a much different amplification factor than a 12AT7 tube, which may have something to do with the sound. The 12AT7 has a gain factor of 65, while the 6211 has a gain factor of 27. I did not compare the Psvane 12AT7's against any other 12AT7's, so no 'apple to apple' comparisons.
I bought the Psvane 12AT7 based on my positive experiences with the Psvane CV181-TII and 12AX7;s, which I did head to head comparisons with many others of their ilk.