for years now I've used rack based effects, controlled by midi. After a long, hard think, I've ditched the rack and bought a line6M13 stompbox modeller from Richtone. It's really opened up my playing and use of effects. plus it's got a looper built in.
http://www.youtube.com/watch?v=vuYEWYSnhnc
Saves a fortune on buying the 100+ fx on offer and I defy anyone but the most anal to distinguish the sounds from the original pedals...
tap tempo tremolo, proper tape echo, several compressors, 9 wahs, amazing reverbs, 2 pedals can control *any* paramter, 144 patch locations in each of 4 groups. You can even route some effects straight into the amp, others via the amps FX send/return.
Practically, it's a perfect economical solution - 1 cable in, out to the amp one board fits all and it's slotted into both my rock, ambient and improv gigs with ease.
I'm convinced....