#1
Just wondering, been looking at these guys for awhile. I hear everything from "Best" to "Worst" Marshalls ever. But Refused and Rise Against are among the bands that use them, so they can't really suck entirely...?
Any advice? I know there are a bunch of differant ones, I'm looking at the 4100.
#2
JCM900s are pro-quality amps. They're more modern sounding than 800s, and generally don't have the fizzieness of the 2000s.
#3
All of them are good if they work for you and provide the sounds you want.

I am not a big fan of the jcm 900. It sounds good, but it just isn't for me.
My Gear
Guitars:
-Gibson Les Paul Tribute (Bare Knuckle Nailbombs)
-Ibanez "lawsuit" Les Paul (Seymour Duncan Pegasus and Sentinent)
-Ibanez S470 (Dimarzio D-sonic and Humbucker from Hell)
-PRS SE Custom (Guitarforce Black Diamond and Lord of the Blues)

Amp:
Marshall TSL100
EVH 5150III EL-34 50w
Marshall 1960a cab

Effects:
Dunlop 535q wah
Boss Super Chorus
Bogner Uberschall
Ibanez DE7 Delay
Electro-Harmonix Power Booster
Fender PT100 Pedal Tuner

Strings:
Ernie Ball Skinny Top/Heavy Bottom 10-52