I bought one and I needed to align it. I needed to shim the base. I thought that the lens was out of alignment with the neg stage, but I found out that the problem was that the lens mounting flange was not very parallel to the front of the lens. I checked the alignment from the stage to the lens mounting plane and it was good. The autofocus is not perfect....pretty good but not perfect. I wouldn't trust it anyway so I was happy.
And Tim......it is really a pleasure to use (and I have a color head...I'm looking for a MC head). If this one doesn't work out, it will be worth trying again.