had a chance yesterday to go over to my friend seth kimmel's shop and compare these three head to head. we used an ai new yorker, and either (or neither) the fishman pro platinum preamp or the hpf pre. using a sweet bass seth built - carved redwood top and maple sides and back. spiros in fifths. some observations:
the dyn-b, running directly into the lowz input of the amp, was too quiet. running through the hpf pre brought it to useable volume. it didn't even work with the fishman preamp.

this pickup sounded the most natural, with a good balance of body and pitch information and nice tone on the front-end of the note. really excelled at bringing out the qualities inherent in this bass - very even up and down the neck.
the full circle was a close second - good clarity, even better bottom that the dyn b. slightly crunchy piezo sound. louder than the dyn b. sounded comparable through either preamp, and better than directly into the high z input on the amp. maintained composure at increasing volume better than the others.
the realist sounded muddy by comparison. best sound was directly into the amp's high z input - neither preamp really helped. i like the sound of this pickup quiet, but when we turned up to where we started to hear the bass more from the amp than acoustically, there was a limited amount of pitch information. it had some pleasant 'old school' to the tone, but by comparison the tone seemed to contain 'noise' that was unflattering, especially noticeable in the higher range of the instrument.
i think now i'll try blending the full circle and the dyn-b on some gigs. the double input on the amp would work for this, but provides no individual channel volume control, so i'll run it through a raven labs blender.
sean p