I built one using the Westlabs transformer set which were used in Matchless amps at least in some periods. With those transformers it sounds very, very much like the Matchless Nighthawk ( I owned one, so I'm not guessing) but with a few additional controls. If you'd like a Matchless Nighthawk (which is similar to the right/EF86 channel on the DC30) and you use the Westlabs transformer set, you'll be happy with the Creme Brulee. I can't comment on what it would sound like with the Ceriatone transformer set, I just ton't know.
With the Westlabs transformers (which have HUGE power and output transformers, which are key to the amp's behavior and headroom and sound), the clean voice is bright and clear and pure and "forward" in the mix, but it can get very dirty when required. It's got that "steely" voice that many Matchlesses have. The master volume works pretty well. The half power switch is a pentode-triode switch, it changes the voice to a darker and dirtier one. Like the real Matchless Nighthawk, it's VERY LOUD for a "15 watt amp." It's got a lot more headroom than most AC15s for instance. A well-broken in G12H is a good speaker choice. If you want it a little less bright, the proprietary Bad Cat speaker would be warmer sounding.