As a guitarist, I am somewhat picky about my tone. I don't spend hours trying to find the "best tone", but I like to try to get 80 to 90% of what I really want. When I'm playing a bass or acoustic guitar I don't mind as much, but when it comes to electric guitar, if the sound isn't right, I get a bit upset - especially when I've spent a couple grand upgrading my gear.
This year I picked up a Roland JC-120 amplifier, and a Boss GT-8 guitar effects processor. The Roland JC-120 amplifier is beautiful in appearance, and likewise its tone. The clean jazz tones and extraordinary chorus effects coming from this amp are virtually unmatched by any other amp available for purchase (after all, it is called the Jazz Chorus-120). On the other hand, the Boss GT-8 is a very versatile multi-effects processor with dozens of effects, pedal distortion sounds, and amp models. The JC-120 is basically an amp to end all amps, at least in the clean department, and the GT-8 is perhaps the most flexible multi-effects pedal obtainable, and superior - at least for the time - in many ways.
I found it rather upsetting, then, that I wasn't getting any of the sounds I wanted. I wasn't even getting decent to good sounds. I was getting tones that would send a cat up a tree. As it turns out, the reverb was turned up on the JC-120 amp, and as soon as that was rectified, things started to look up again. The reverb knob was thus dubbed the "suck knob." When I thought about it, it made sense. When you already have reverb running through the GT-8, you don't want additional embellishment from the amp. You want to keep the sound on the amp as clean and crisp as possible (which is what the amp does well).
As cool as it is to have this gear in my possession, I can honestly say that not many of my practice hours were spent exploring and understanding it. Moral of the story, know your gear. With the right settings, and a little patience, your gear will work for you. If you fight it too much, you will get goulash.