Anyone have experience with NOS 6gh8's?

I converted my Dynaco ST70 for 6gh8's as small signal tubes replacing the original 7199 configuration. I would like to know if anybody has experience with any NOS 6gh8's and how do they sound? For example, differences between different brands of tubes. I am particularly interested in finding out how RCA's and Sylvania's sound.

I have some Bugle Boy 6gh8 equivalents, I will post results with these tube as soon as I have the amp up and running. I just finished overhauling it, and will test it tomorrow.

I am interested in the 6gh8's, though. According to my Internet research, they sound better than equivalents.

Any thoughts? Thank you!
By the way, the Bugle Boy's are ecf82. They actually sound nice -- very musical, not technical, nor harsh. They don't sound grainy, but a slight bit veiled. Let's see when the tubes break in; I have only run them for a few hours. I must say that I really enjoy their midrange, very sweet. The bass was not lacking. Perhaps this is partially a product of my adding in the SDS labs capacitor board that increases the power supply filter capacitance.
Anyway, I will play around with different 6gh8 and equivalent tubes and write more as I do so...

The Bugle Boy ecf82's opened up after breaking in. They sound really sweet in the midrange and are nicely detailed.

I also tried Amperex Orange Globe 6gh8a, Raytheon 6gh8a, and General Electric 6gh8a.

I would put the first three at the same level of performance. All very satisfying with great detail, smoothness, soundstaging, etc. The differences are subtle.

The General Electric tubes never quite opened up into sweet sound. They are not bad, per se. But they are my least favorites in the group. They seemed a bit edgy compared to the others.

I was surprised at how easy it was to buy these on ebay -- all NOS and tested. They were all cheap! The Bugle Boys were the most expensive, but still not near the cost of NOS 12ax7's.

I wonder if I am the only one who modified his ST70 to use 6gh8's instead of the 7199 driver tubes.