Eddie, I don't know much about those particular tubes but I believe they are made from the same manufacturer that made my reissue Genelex KT-77's that are in my two Anthem1 amplifiers. I have about 6 sets of tubes I have had in and out of the Anthem's and the Genelex's are beyond any doubt a fantastic tube.
Normally when I swap out a tube or tube set I think to myself, "Eh, I like these better or worse than the last set". No big deal type of thing, it's just one preference over another. That said, when I put in an octet of the Genelex's? I was flabbergasted. I had never had a tube, or set of tubes, that made such a dramatic difference and change in almost all aspects of the sound. It was comparable to upgrading and amplifier or set of speakers to a much better pair.
While I have no direct experience with the tubes you had mentioned, based upon my experience with the KT-77's, I definitely wouldn't keep them off my long or short list of things to own. As George mentioned, drcilantro over at CP would know more. He's the cat that hooked me up with the octet of KT-77's and I believe he's got some of the one's you have mentioned as well.
You may also want to get a hold of Jerry12 [He will be attending CF this year] and see if he has anything out of the hundreds of tubes he has that you may be interested in.
In search of accurate reproduction of music. Real sound is my reference and while perfection may not be attainable? If I chase it, I might just catch excellence.