Chad, as you may have found, there are appr. 56 references to Dr. Balderston. BTW, what are your concerns about metal-on-metal? I personally don't like this design, but it's only my opinion. We've been arguing the pros and cons of this design for six years now!
In case you've not seen some of the past topics on wear debris, which includes Metal on Metal:
http://www.adrsupport.org/forums/f49...r-debris-6280/