I've always been a skeptic when it comes to trying to cram too many gizmos in one box. As MattG reported earlier, they never seemed to do each effect justice. But the technology ages, there seem to be some really good 'all in one' units out there. The Pod series gets great reviews and you'll notice quite a few of them as part of the pro's setups. Boss makes really tough, really good sounding pedal boards. Again you see a lot of Boss boards if you look at the big boys rigs. I've owned a bunch of them. I have a cheap Digitech RP200A that I use as a headphone/practice/song learning unit. It has some passable sounds and is easy to tweak. It also has a mini plug line in that is good for learning tunes. I have patched it into my recording console at home. The tones do not hold up well under close examination. I have a couple of Yamaha products. A Magic Stomp and a DG Stomp. The Magic Stomp has really good effects and less than OK amp modeling. It is not practical to use live because it is really cumbersome to fine tune a patch if you are not hooked to your computer. The DG Stomp has much better amp modeling but a limited amount of effects to choose from. It is easier to use live but three years of tap dancing lessons are required to navigate it. I recently bought a Line 6 M13 pedal board. It is essentially every Line 6 pedal built into one unit. It has no amp modeling which suits the heck out of me. It is all stomp boxes. The sounds and ease of use are well above fine and as the advertising promises it is "Bonehead Simple" to program. With all that being said, I've walked both sides of the tracks. A rack of processors with a midi foot controller, a few multi effectors, a pedal board that required two humans to carry and set up. All of the rigs have served their purpose and then I moved on.... and came back... and moved on again....
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The music business is a cruel and shallow money trench, a long plastic hallway where thieves and pimps run free, and good men die like dogs. There's also a negative side."
Hunter S. Thompson