More than happy to weigh in for @defbear and @rigo! Yes, I had the Master-9, which is a slightly suped-up version of the amp section that's inside the Master-11. You've got a great device there, no doubt, but if you are on the fence about the LAu and wondering if it is worth it, don't be. The Liquid Gold absolutely kicks the snot out of the Audio-GD.
The LAu feels so alive compared to the AGD. The AGD is very proficient from a technical standpoint, IMO, but it lacks magic. When you're listening to the AGD, you're listening to a great setup. When you're listening to the LAu, you are there.
IMO, one of the most magical parts is that the soundstage on the LAu doesn't seem to have any specific shape or boarders. There is just a guy, about five feet to my right and 60 degrees from center playing guitar. Until you hear that, it is nearly impossible for me to truly explain the experience to you. There is transparent, and then there is transparent. There are no headphones. You are in the room with the musician. It is a highly emotional and magical feeling that you have to experience to truly know.
The warmth and treble control are without equal. It is my all-time favorite amp for the HD800 and it makes the JPS Labs Abyss absolutely sing in a way you can never forget. The bass is powerful and very lifelike. Compared to the AGD M9, the LAu hits harder than a cement truck. Again, it is like being there. It is just so incredibly dynamic, fun and engaging.
As far as value goes, I had the good fortune of being able to compare it head-to-head with the $7,000 Wells Audio Headtrip for about a month, and the two are absolutely neck-and-neck. If you think the Liquid Carbon was a great value, competing with amps that cost $1,000 more, consider the fact that the LAu can hang with an amp that costs $3,400 more, after your discount!
On a final side note: I have witnessed dozens of people try the LAu - both at the February Chicago meet, and in the month after (at my house) and I have yet to see a single person who isn't absolutely blown away by it. My favorite thing is when my non-audiophile friends try it. I always love watching that first moment when the music starts and they turn to look at me in wide-eyed shock, lol! These people have tried plenty of my other equipment, but nothing like this. It's just on another level. I get a kick out of it every time!
But how do you REALLY feel?