Weird product at this price...
I do think it sounds pretty good (better than the Katana's high gain sounds, at least without a bunch of Lambchopper-style tweaking)
Obviously they're doing this because they own the brand, but a lot of the normal arguments for this sort of thing kind of become moot with an amp you don't need (or even necessarily want) to crank.. the selling points basically just become "well, you can use headphones and record it direct", "it's not cheap, but it's 100USD cheaper!", and "it's not compact or light, but it's lighter!" I guess there's the upkeep argument, which is more relevant with amps that use so many tubes, but the repairability and warranty aspects makes that more complicated.
I feel like Fender / EVH should just be doing UA amp pedal type things, even if a mini head format or something, piecing out their TMP models. Sell them to plug into their well-liked FRFRs.
Though I guess the appeal of these for a lot of people is the whole "guitar speaker and cab in the room" thing. Maybe they should just create a powered cab that uses guitar speakers. If the power amp is decent, there's probably a good market for that anyway. Too bad that Tone Master Twin doesn't have a power amp input / FX return. You could grab that for 1300USD, get 2x12 and 200 watts, and plug a Tonex One, UA Anti 1992, or used HX Stomp or Nano Cortex in and end up ahead AND with the Fender amp sounds too.