I got a Bass pod, the one that became the xt, a while back (think it was about 2002). I have never used it live though. For me its really a studio thing, lots of tweaking is needed before you can get a sound that you really want. Once you get that sound, its great, but it can take ages! The effects are pretty cool and do the job. Never really found the footboard to be that much use though, you couldn't really switch between one sound or another without a big gap where one sound faded out then another sound faded in. Though that might not be case with the new models, but I can't say for sure.
Outside of the Pod, I tried a couple of the Lowdown combos, I wasn't blown away by it, but there wasn't anything seriously wrong with it. Also, I know its for guitar, but the fact that the Spider III has an 'INSANE' button kind of puts me off seriously considering them. I also hate the Variax.