You really need to be careful reading online reviews of amps! I would say that most of the people posting about this 12 tube Tri-Mode 100 watt head pretty much FLAME IT!!! They call it unreliable mainly... fizzy, uninspiring, thin and even ugly.
Well.. I guess I got one of the only good ones. I just picked it up. $300 including the 4 button footswitch. Here is my review playing it through a Blackstar 2 x 12 cab loaded with 80w Celestions and a Crate 4 x 12 straight cab loaded with Celestion T75's.

Clean channel. This is Fender Twin Clean. Its beautiful. Sounds dead on to a Fender clean.
Overdrive 1. Anything from blues to classic rock to metal. It has a contour control that allows you to sweep the frequencies which basically goes from scooped sounding to midrangy Marshall roar or anything between. I will say that this is definitely a JCM900 Marshall tone based amp.
Overdrive 2. Pretty much the same as Overdrive 1 but a little more gain and a little more modern sounding.
You can easily use Overdrive 1 for heavy metal rhythm and Overdrive 2 for solos.
The foot pedal does channel switching, overdrive 1 and 2, reverb (real accutronics btw...) and effects loop.
The rear panel has a knob that switches from Class A, Class AB and Solid State Rectifier mode.

People call it the poor mans Mesa Rectifier. This proves to me that most people that review this amp don't have a clue and are calling it this only because it says Rectifier on the front panel. This amp sounds NOTHING like a Mesa Rectifier. I think the reliability issues are mostly due to user errors. These are clueless kids that bought them from Guitar Center and mistreated them. You can blow up just about any tube amp if you mistreat it.

Anyway.. back to the review... the amp has a Master volume, resonance and presence controls, separate EQ's for clean and overdrive channels and switchable contour for each of the overdrives. The effects loop has level controls on both send and returns. I opened it up and inspected everything. This amp is made very well internally. I would say its not as good as a Mesa but its better than a Marshall JCM2000. Its very neat inside. For tubes its running 4 6L6's, a big bottle rectifier tube and 6 12AX7's!! Its a ton of tubes. Cab is 6 ply birch. Very well made. Chassis is a little on the thin side but I don't intend on dropping the amp off the truck. They say they run hot. Mine doesn't.

Its a great amp for super cleans, classic rock, 80's metal and todays heavy stuff. Its very powerful. Its also fairly quiet at extreme high gain.

I heard reviews that it sounds thin live. My guess is those users have their mids on 1 and the contour dimed out to scooped mode. I have read many typical settings online and the kiddies that bought this amp and who complain about it are usually posting the worst settings I have ever heard for live use.

I have been A/B'ing this amp against my 6505+, my Rivera, my Soldano and all my other amps and it can hold its own. If your in an 80's hair metal band like I am the B52 AT100 is a great choice. Its forgiving, its easy to dial in and it sounds great on any channel and its not even that picky when it comes to cabs or speaker selection or guitars. I read that Bruce Egnator designed the preamp in it. I wouldn't be surprised.