I like Matchless amps, especially the Chieftain 212 I've had for years.
It's loosely based on an RCA Bassman preamp section, running into Matchless' own EL-34 power section with 5AR4 rectifier. Plus reverb.
The tone is a very tubby sounding clean tone that fills a room like a halfstack. It's a very fat and toneful amp. As it overdrives, it goes into the JTM 45 realm but will never be a truly great highgain lead type of amp, without an OD. The level of gain is more like George Throroughgood.
Sitting next to a Bassman, it's a little fatter sounding due to the 12's. It's breakup is less honky than a bassman....slightly more Marshall-like. Compared to most Marshalls, it's cleans are far richer and they both handle volume really well without farting out. It's close to an old Marshall sound, but still has a bit of that American sound in it.
It's a sound that you either like or you don't. One thing is for sure.....it's pure tube goodness. Totally glassy and harmonically complex. They're really a modern classic.
The Chieftain is more of an original Matchless idea, while the DC-30 is basically an overbuilt Vox AC-30.
Oh, and the Sampson era was pre 2000/2001 I believe, but the new owner was also an early Partner, Phil Jamison. The idea that Sampson era was superior is an internet myth. According to Phil, Matchless's attention to detail is even better now than in the 90's, and he's also building new models that are outrageously great like the King Cobra and Independence.
It is true that Sampson era amps will prove to be the most collectible in future years, just because that was the original incarnation of the company when Mark Sampson built them.