samthase,
If you're considering a new CV 90mm then you should also consider a used 90mm Tele-Elmarit if you can find a clean one of the thin variety. Check the Leica list to make sure its serial number is in the newer range which means you could also get it 6-bit coded if you chose to do so down the road.
I've never handled or used the CV 90mm but I do have the Leica T-E and have never been disappointed. Plus, as a tangible benefit you also get a one-stop speed advantage with the T-E. It is also a small lens which makes it handy to carry when traveling.
The 75mm option is a different story since the CV alternative is so very much more affordable that either Leica option. (Full disclosure: I sold my 75mm Summiux and bought the 75 Summicron as soon as the latter was announced. I've never handled nor used the CV 75mm lens but those that have love the lens.)
-g