I have an older version of the SX200 I picked up used at GC for under $200.
It's alright. The cleans are clean, the reverb is reverby. The distortion is pretty blah - I guess it's usable, but compared to my Jekyll & Hyde, it's a joke...still, I've heard worse.
It's my only amp at the moment (out of financial necessity, not choice), and it gets the job done. Using a distortion pedal, it sounds pretty decent. I played a gig with it last week and didn't have any complaints.
If nothing else, this thing is LOUD. About 2.5 gets me louder than our drummer. 3 is cover-your-ears worthy...I've never turned it up past 5. I don't want to.
A/Bing it against, say a Twin Reverb, the SX is a huge pile of crap...but just for a kickaround amp that's loud enough to gig with...it's worth the money if you find it at a good price. When I do manage to get myself a nice amp, I will probably keep it around...it has two channels and is beefy enough to handle my wife's bass at low to moderate volumes. It will make a nice practice amp that we can both use at the same time.