Being the guy that was pro-Digitech, let me elaborate: I first had a Zoom G1. It was great, but didn't have midi output for recording. So I upgraded to the RP250. My consideration was driven greatly by cost. At that point I could not justify spending hundreds of dollars on an effects pedal. I just wanted something so I could get some chorus, some compression,etc etc... Basically something to play with. The RP250 fit this bill for about $150 at the time.

I have to say the quality of effects was much better than the ZOOM G1, which only cost me $70. So, from that I can surmize that the more you spend, the better it will get. Like most things, I guess. :rolleyes:

One little thing you can do with a multi-ped that you can't with separate boxes is have an instant switch for a group of effects. Lets say you are doing an intro that's clean with some nice chorus & reverb, then you want to switch to to some OD effect with compression. It's hard to do that in the space of a beat with multiple boxes to press (unless there is some trick I don't yet know). With the Digitech, I can set up effects groups side by side, so I can get instant switching like that.

All that said, it's important to be aware that a modeling pedal is just that: electronic simulation of effects.