I just played an AC for the first time today at Jive Sound... I was in there tooling around, and someone else happened to have brought one in to demo an amp with. I asked him about it, and he was cool enough to let me put in a few minutes on it.
I was extremely impressed with the sound... it was a super-versatile bass that went from big and thumpy to bright and punchy with no effort. Jimmy preamp seemed pretty sweet too... it's hard to describe, but I felt like working with this preamp was easier than working with most others. It seemed like it was very well-built, and it was a breeze to play. Suffice it to say that my AC GAS has progressed from moderate curiosity to all-out wanting. Alas, I have many (well, two, which is many for me) irons in the fire, so I won't be making that call for quite some time. Still, it's a great feeling to have finally played one.