I personally like the Digitizer in the MP-1 effects loop. I think MJMP mentioned earlier about how it has great chorus sounds, and that it does. The Digitizer has a bright edge to it, or at least mine does, which works very well with the MP-1's strengths IMHO. I really dig it, it has a unique character that endears me to it. Just to give you an idea, my rig has one of the "Holy Grail" delays in the Ibanez AD202 (which I LOVE) already connected in and I STILL use the Digitizer more, and not just because of its relative versatility. I would give it a go given the opportunity Mr. RandallRG.
And to add on to MJMP's and Kim's point on the BBE debate, i used to use an Aphex Aural Exciter (with Big Bottom) with my guitar rigs (its the equivalent to the BBE). I found that my sound got broader and more defined, but less punchy. I would rather go with more amp headroom if the opportunity presents itself than go the BBE route. It works in certain situations but not all. On the other hand, it is perfect for modern bass, so it is practically welded to my main bass amp.