well, I'm a pedal nut, i do not like multi-effects at all.. that being said, if i was going to go for a multi effect unit, it would be the g system or nova system. I was very suprised by how good the nova system was when i tried it, and the G system by all accounts is the big brother.
on the caveat that i'd only use them for time based effects. would still keep separate drive and wahs