A redline600 was my main gigging amp for a few years. They don't really have much of a baked in "sound" of their own. Some woyld consider them sterile and weak sounding, others would view it as a blank canvas. I'm somewhere in between.
Advantages:
Lot's of EQ, can make it sound like pretty much anything.
Footswitchable graphic EQ, can switch on the fly from band mix tone to solo tone, or finger tone to slap tone, etc.
Stereo poweramp, built it crossover, biamp capable or can power a lot of cabs.
Low resale value, can pick them up cheap.
Disadvantages:
All that eq can be confusing to some. It's not a plug-n-play amp. Probably won't like it that much until you turn some knobs.
Seem somewhat underpowered, but that could be the lack of a baked-in, powerful sounding eq curve.
Hard to get repaired if you need to. Even carvin stopped making circuit boards for them and is rather just offering sort of a pro-rated discount on a new amp rather than fixing them.
Low resale value, have to sell it cheap too.
In addition, some of the inherent problems when they start acting up are dirty or unseated ribbon cables. Easy fix you can do yourself if you know this. Mine fried after a few years but in fairness, that was after a few thousand hours of abuse by someone who at the time, didn't know all that much about what they were doing......me.
