nextreme—Thanks!
I was hoping to shoot with the 90/2.8 Hexanon today, as a comparison to the Elmarit. I have the R-D1 and Hexanon in front of me now, but unfortunately, the SD card is at home. Oh well!
Anyway, some physical comparisons: the Hexanon is a few mm shorter, and a touch narrower in diameter. It is a little lighter. The focus throw of the Hexanon is shorter, and the focusing action feels better damped than the Leica. Both take 46mm filters, and in use, they feel very similar. At a quick glance, they look identical.