I’ve tried Matchless’s a bunch of times (including the HC30 and DC30) back when Ultrasound studios was in business and honestly was never crazy about them. I remember them having this hard, unpleasant glassy quality to them and didn’t feel good to play. They also had this filtered (to me inorganic sound) quality that most recent made amps tend to have
I’ve didn’t tried lots of el84 and vox type amps boosted, but not the matchless itself. They do to take boosts very well, but would be a different flavor than your boosted Marshall and not really be the best choice for metal or hard rock imo
I’ve basically tried and/or owned them all when it comes to EL84 Vox type amps (Top Hat, Savage, Tex, Sommatone, Bad Cats, Star, Divided by 13 RSA31, Morgan, Bruno UG, others I’m blanking out on). I liked the Tex best of those and maybe Savage Schatten was my 2nd favorite, but I’d still say save up for a good vintage vox and it’ll be better than all of those if you’re going for that kind of tone
I had the same experience with all the countless Marshall and Fender inspired amps I’ve tried. They all sounded worse than the real things except for maybe the Wizard’s, which kind of have their own sound anyway
The Komet amps may also be worth considering. They’re trainwreck copies that sound great and kinda how I’d imagine a hot rodded vox sounding with some Marshally qualities in their as well