Although this is an old thread, it's taken me a while to get the hours up on this amp so that I could break the speaker in and give a verdict.
Well I've been playing it a lot lately and at decent volumes, mainly with my SG Standard (EADGBE tuning) with the Cold Sweat pickups, 50's style harness with CTS 500K pots and 0.022 uf PIO caps, and Tonepros bridge and tailpiece with top-wrapped Hybrid Slinky strings.
All I can say is that it sounds amazing, with so much CRUNCH! The Cold Sweat guitar sounds better there than through the 6534+, which I guess is EQ'ed for the DGFCAD guitars with Nailbombs and Stockholms.
I can highly recommend The Wizard as a replacement speaker for the Classic 30
Also, I handballed the Mooer Black Secret to the other guitarist in Terania for a new bike helmet (he owns a bike shop). He knows it's a squeally pedal (and it squeals through his Mesa) but he wanted it just for that kind effect. Good, I've gotten rid of it. Really hated that pedal. The only problem is that I still have to listen to it at band practice

Ive heard that the wonderful crunch channel on my beloved JSX is a tweaked version of the Classic30 overdrive channel-will be curious to hear what you make of it :)
Actually I'd say it would be pretty similar, as the sound I'm getting from my Cold Sweat Gibson SG through it is similar to the sound this guy is getting out of his Cold Sweat PRS Tremonti through his JSX.
https://www.youtube.com/watch?v=E-PUDxeS8T8Not sure which channel that guy is using but there are a lot of the same tonal characteristics, especially that crunchiness.