John the are both very good the ZM and VC. I would tend to say the ZM is better and reason being its going to have more pop to it , more micro contrast. Center will be sharper more wide open and the corners come to life better sooner on the ZM. Now the CV just has a softer feel to it , maybe more gradual type of feel but and the corners are not there until F8 and you need to focus before infinity with it. Big price difference though and the CV is a really nice lens but I think most folks may like the ZM better even though its bokeh is a little strange sometimes and the CV is very pleasant. I would say from me that the CV is a little harder to work with as you have to keep the more field curvature in consideration when shooting. Again I like them both but I feel after having the CV twice now the ZM just fits Guy better.
