I got the boss gt-10, i think the distortion amp tones are not the best(before tweaking) , effects wise there is very good modulations and wah, whammy etc.
I dun really like the pitch shifter though, i think its really lousy as compared to what i had on a zoom G2 unit though hahah
I had a zoom G2.1u once, effects were generally ok. They were prominent but not very tweakable, eg flanger phaser etc. Distortion sounds were great for high gain, great noise gate, but there was kind of a very stratchy sound when playing solos, could be my fault though, too much gain or too high noise gate threshold etc lol. I never really tried using the whammy function on that as i didnt really know i had a WHAMMY in that thing then ... DAMN
I believe that u can consider the zoom g9 too, distortion sounds are definately going to a good with a preamp tube to warm up your guitar input and a postamp tube to warm up your sound going into the amp/mix. That pedal can allow you to do whammy+wah at the same time, but the quality of the foot pedal may be dissapointing as i have seen from reviews, like it may become squeaky after prolonged usage.
http://www.youtube.com/watch?v=NtTfkDNewYg
kiko loureiro demoing the whammy+wah feature
I heard POD x3 even better than POD xt and somemore it has vocal n bass preamps, do check that out too