Nuance had some pretty bad reviews here:
http://download.cnet.com/Nuance-PDF-...-10973909.html
When I see the word "crash", I shudder. Bad customer support is also scary.
Adobe Acrobat is a bear to use, but there are several books you can buy to master the program. Adobe will be around for a long time. Who knows how long Nuance will be in existence?