I've had the pa2v2 for about a year now, first i just used it for my k272's but it does wonders for any cans.
And Gary is an amazing guy;
The first amp i recived was a bit glitchy, i emailed him and apparently i had gotten an experiment amp that got mixed in with the others.
I got a replacement within a week, which is impressive cause i live in sweden.
it's been working flawlessly since.