I have the rackmount with the chorus/echo unit, and a bass belt unit. I got my bass and first set new, but then after the original rackmount was stolen, I picked up another set on ebay pretty cheaply. They are a bit noisy, and work a lot better if you have the footswitch for them.
I used to have the belt unit too, but the original not the new lite models.
They are all a bit noisy but if you want the Tom Scholtz processed sound, then they give it!