Nuance PDF Reader works quite well on mac except for a little rendering bug when scrolling but that seems to be present on all pdf reading software I've tried so far under CrossOver.
Using the native renderer driver improves the scrolling but disappears the window and top menu.
I've used the web-based file conversion and the program correctly fires my default mac browser and uploads the file correctly.
The program is Silver/Gold status but I tend to leave them a ranking of Silver until I've played with the program for a while to check for stability.
Please note: Nuance PDF Readers is a bit of Ad-ware that constantly advertised Nuance's PDF Converter, but doesn't impede functionality.
(If there is a way to turn this off I haven't found it yet.)