I have to say that for myself that the lack of third party support kind of defeats the purpose. I would have thought that the purpose of adding audio recording was to minimize the need of using rewire. The effects (and many of the sounds) in Reason really don't live up to my desired expectations.
Still, Reason is kind of a cool program for what it is. Good sketch pad...Easy work flow for creativity. I haven't used Reason for a long time. I doubt that there are "numerous hits" that were created using Reason entirely, except perhaps in the Techno genre. Most of my friends who are creating electronic music have switched to using other tools. Peace