Price paid: $ 600
Purchased from: Craigslist private seller
Features — 7
Made in 1994 and still working great. The reverb tanks were shot, but I use pedals for that anyway. I wished it didn't have a shared EQ though, it would have been a lot more usable if it had two separate EQ's (although both channels were still not resonant enough even with the bass at 10). I heard that these amps have clipping diodes (solid state) in the distortion channel. This doesn't change my rating, I just thought it was interesting. It doesn't seem right that a Marshall tube head should have LED-based distortion. For the record this was the 4500 (50w Dual Reverb) model.
Sound — 6
I actually liked the sound of this amp. It can be quite controversial but it honestly wasn't bad. I was pleasantly surprised by the clean channel, I'd thought Marshall couldn't do cleans at all. In retrospect it's no where near as full or sparkly sounding as my DSL, but still pretty good. No one buys Marshalls for the cleans anyway. The dirty channel was good, but you need to crank it. Otherwise, have a tube screamer of some sort on handy, and maybe an EQ pedal. It has the tendency to be quite "fizzy" or "buzzy" or "synthetic" sounding due to the somewhat artificial distortion.
Reliability & Durability — 9
I got this secondhand in 2016. It was 22 years old, and it still fired up and sounded good every time. A few tears in the tolex, but they look even cooler with wear. Some of the outputs out back were a little finicky (the effects loop was kind of screwy and temperamental at times) but I expect some wear from a 20+ year old amplifier. It gets pretty hot after a while, too, and doesn't have vents like the models on either side of it do... kind of a design flaw if you ask me. Other than that, the thing's kind of a tank.
Overall Impression — 7
Overall I do not regret owning this amp. I was a little let down about the sound of its distortion (I wanted it because 900's were used on almost all the Rise Against records... turns out there must have been some studio magic going on there) but I got it to sound pretty close to the way I wanted it, it just wasn't a walk in the park. It's not a purist's amplifier but I'm not a purist and I'm sure it's even surprised a few people and changed a few minds. It's no less than a trusted amplifier that has stood the test of time. If I were to play one again I definitely wouldn't say no.