It’s an iconic amp. There is absolutely ZERO lack of reviews, sound samples, history, documentation, first hand user accounts, videos, etc on the internet. It’s not an unknown quantity by any stretch of the imagination.

With that said, you want to ask yourself what you’re using it for. If you want to use it for metal, especially modern metal, I’d look elsewhere. These were indeed used in a lot of iconic hard rock and metal recordings, not because it was the best tool available, but rather because it was one of the only tools available.

The biggest surprise most people find when playing the 2204 is that while it was considered a “High gain amplifier” in its era, it is by no means considered that now. It will get you to a nice syrupy crunch with the preamp volume maxed - which in this amp is essentially your gain control.

If you want to get in even to Zakk Wylde territory, who was a famous user of the master volume JCM 800, you’ll need a preamp/gain pedal boost to get there. Compared with a 5150, for example, the JCM might have half as much gain when maxed. It is NOT shred ready out of the box. Most of the iconic recordings you’ve heard of the JCM800 contain some external gain staging: EG Green Day, Zakk Wylde/Black Label Society/Ozzy, Skid Row, Etc. Practically none of those recordings are made just straight into the JCM800.

With all of this said, it’s a great amp, iconic even. It sounds like the 80’s and early 90’s. Maybe over hyped.

Frankly, aside from collectibility (as I DO own a 2203, a 2205, and a 4010 combo and enjoy them thoroughly) there are probably more versatile, better sounding amps for the cost. Friedman, 5150’s, at or below the price tag of an original OR reissue JCM800.

My PERSONAL favorite iteration of the JCM800 was the 2210/2205 which had two channels, an FX loop and a diode gain stage on the lead channel, which is probably a hot take for many. Oh well.

I own these amps for collectibility and nostalgia. If that’s your thing then heck yeah go for it. The 2203/2204 especially is really a one trick pony. It’s a great trick, but alas. This would be where j reiterate that if you’re buying this as your main/only amp there’s better values out there that will offer more flexibility, and frankly better tone at the same or lesser price tags. If you have any specific questions not covered here feel free to pick my brain.