^Ahhh don't say that they don't sound bad but there is definately a difference. Both my uncle who is a bassist and his guitarist use multi effects. simply because they can program everything to what they like and make different tones you couldnt get out of just one stompbox. (vintage modelling and such) and their tone is pretty awesome live and in teh studio.
I had a mini mini multi effect pedal, a korg ax10, which was not so good because there were only 2 switches to controll the effects. I like multieffects to have separate switches for individual effects, like one for od/dist, one for reverb/delay and several others. Those are more expensive.
This is the one my uncle's guitarist uses. It's valve powered and although I dont realy know what that does I think its a really awesome multi effect pedal because you can pretty much controll everything without having to buy single pedlas and you have a bunch of cool efects that you never even dreamed of buying as single pedals and its really fun.
I like the 2 wah/expression pedals that the thing has.
Also, the bigger the multi effect pedals are the better, that way you get more controll and options over your effects.
phew.
I'm still a pedal guy though. dont like the digital feel