That's a follow-on to the Generis GT-2, right? Ought to be an interesting piece of hardware. It definitely provides a very different character from any of my other tube mics. I don't know quite how to describe it.
Let me put it this way, if I want to get a smoky sound out of tenor singing in my low register, this is the mic I'd reach for. I'm not sure how much of that is the mic and how much is the tube that came in it, though. I haven't opened it up to see what's in it.