I just switched to fedora 17 and noticed no major problems.
Note that my upgrade method is about to make a clean install and then upgrade then restore several configuration one by one.
The typical example is on Firefox and Thunderbird where the "cache" space is 2GB for the latter.
Noticeable facts are that boot time is faster (comfortable on a laptop I use to completely shutdown ratehr than going in sleep or suspend state), and EMacs 24!
I espacially thank all the community around Fedora so that I have a great bunch of software to work with.