I've used C1 for about 2 years now and love it--don't want to switch but I have Leaf Valeo 22 files from 2005 which LR reads just fine, but C1 pro will not. It doesn't make sense that Adobe would support Leaf 2005 files and Phase One, the parent company of Leaf, doesn't. Possibly I'm not doing something I should be, but it has happened before and Phase One is forcing me to buy Adobe. So if I'm incorrect, please tell me as I'd really like to stick with C1 exclusively.
This is sort of a rant, but I'm also hope that someone connected to PHASE ONE realizes that for a while, the older Leaf backs were the best there were and those of use who had them have hundreds or thousands of images in our archives that need to be processed--I bet it'd be good business!