Anyone compared a KGSSHV with a KGSSHV Carbon?

The Carbon is much much better than the KGST, especially paired with a 007. It's also notably better than any KGSShv (I've heard 4 variants of this amp), though a Mjolnir KGSShv is indeed a fine choice for this headphone too.

I also love tube gear, but the 007 (I had a Mk I) simply sounds better with the Carbon - this pairing is even slightly better than the 007 / BHSE. The only exception here is the DIY T2 (tube), which sounds better than any other amp, with almost any top 'stat, but is very difficult and expensive to source (and the Mjolnir guy won't even admit it's better than anything he can build).

The 009 and L700 can get a little aggressive/fatiguing on the Carbon and some KGSShv variants. That's why I prefer tube amps with those headphones (and again, they're at their absolute best on a DIY T2). But the newer 009S has a warmer tone and matches extremely well with the Carbon.

Hej mulveling

Everyone says that the Carbon is the one for 007 Mk2. But it's also twice the price of KGSSHV. So, is it really worth it? 
My "primary" DAC is a LAB 12 DAC1SE which uses a E88CC tube, so if I buy KGSSHV I have the oppertunity to tweak the sound a little by rolling that tube.  
It's really a hard choise, especially when you don't have the possibility to listen to the amps before buying.
Anyway, I really appreciate your thoughts. Thanks!

The Carbon is more dynamic, more detailed. Notably larger soundstage and better bass impact (and these are the Carbon’s particular strengths vs. other high-end electrostatic amps like the BHSE). The 007 is a notoriously difficult headphone to drive well enough to "max out", so the difference is quite audible. You won’t bridge this kind of gap with any amount of tube-rolling.

Now is it worth it? That’s the tough part of this hobby. What qualifies as diminishing returns for one person will be the eye-popping improvement than puts someone else into the music. And the KGSShv is a quite excellent amp, no doubt. For me, this upgrade would be worth it. I think "source first" for traditional systems shifts more towards "amp first" (but source still crucial) for Stax 007 and 009 headphones.