Nice info. Intersting I like the Sylvania's. I will get a pair of the RCA's to trial. They look like the same construction as the 6AS7G version. So I was avoiding as those suckers are very noisy in my amp. I will give them a blast tho.
Edit: just purchased a pair. They will take a while to get to me tho. I'm at the ass end of the world.
You live in Hawaii too? Nah, just kidding but man does MassDrop take forever to get stuff here, still haven't gotten K7XX from last drop, was shipped out 3 weeks ago.