Experience with Dilog DQ696-20?

Anyone have any experience with the Dilog DQ696 ESDI disk controllers? I just installed one in a MicroVAX III and I've been getting really _dismal_ performance out of it. I had it misterminated for a bit (the middle drive (of two) was terminated rather than the end drive). But I fixed that without any increase in performance. The format/block analysis took about 10 hours for a 600MB disk. The interleave was set to 1 but that seems pretty standard these days, should I up it to 2 or 3? or perhaps reduce it to 0? The drives are Micropolis 1568's so they're nice fast drives. How about Q-bus priority? I moved the Dilog to the slot just after the DELQA so it its CPU->DELQA->DILOG->TQK70 but that hasn't helped either. Any other suggestions or are these things just slow? --Chuck