I have a Darkglass Microtubes 900, which has proven to be a curious item to carry to gigs. They don't offer a rackmount kit, and they have discontinued the bag for it. It's just big enough that it isn't easy to throw in most gig bags, and while it is certainly sturdy, I'm still hesitant to just toss it in a bag of cables.
I've tried a couple of different options over the two years I've had it; i've put it in a Gator mixer bag (which is almost the perfect size for it). I've also rack mounted it to a 2U clamping rack shelf, which works great, and allows me to put it in a rack with a power conditioner so that I can just plug in speakon cable and a power cable, hit a power switch, and i'm good to go.
HOWEVER, for smaller gigs, where i'm just using a 2x12, it seems kind of ridiculous to haul the 6U rack unit i'm using to house a "small amp head".
What is everyone else doing with their small amp heads?