I have been using a Blond Oxblood Super-Sonic head as my main gig amp for a few months now. I sold my TSL-60 Marshall head after buying the SS.
The cleans are nice but the Vibro channell is a little twangy I love the Baseman side though. The burn channel smokes.
The amp really sounds good after a re-tube with a NOS late 50's Mullard long plate in V-1 and Chinese late 80's production Shunghangs in the rest except for the JJ ECC81 in the PI and a set of JJ 6L6's.
The first ones were all over the place in tone due to some mistakes in the bias settings from the factory and some sounded pretty nasty. This was corrected early on and they are pretty consistant in tone now. The SS still will benefit from warming up the cold factory bias though in tone.
Overall I love mine its reliable well built and sounds GREAT!
Here is a clip from Church last night with me playing my Pearl Pink Carvin X220R through the Super-Sonic head on my late 80's Fender 2/12 cab.
http://www.box.net/shared/9jw1nhwskg