I can certainly understand waiting for RTM if, like me, you have dreamspark access or another way to get it free (legally). But I would definitely recommend the RC for anyone who can't get the RTM free.
If history (or common sense) is any gauge to go by, the RC version will expire.
Visual Studio EULA wrote:
Regardless of when you first install the software it will stop running on 15 January 2014 and your license rights to use and distribute the software as described below will also end on 15 January 2014.