Several people have asked about it and I thought I'd give a short review. I was looking for something small,light and powerful. It's small 12X12X3.5 and about 18 lbs same size as a Mesa Walkabout and WT400/300 so I'm actually using a Walkabout gig bag for it (Eden is out of stock on their bags). It's great just carrying it over my shoulder with my bass. I think it's better than the WT400 because of the more power (300w at 8ohm/500w at 4ohm/620 at 2ohm)and the speakon jack with the same sound as a WT400. I like it more than a walkabout(fans on all the time) because 550 fan doesn't come on until you're really pushing it. It has one tube a 12AX7 which give it a warmer tone. I got one of the first ones and it had some workmanship problems which were taken care of by my dealer (i.e., didn't have the proper insulation so the cover would vibrate against the heatsink with every note). I'm still trying to dial in my sound since it's very different sounding compared to my former SWR Bass350 head. Overall, I'm happy with it.