I've been running Fedora 7 for almost two weeks. To be honest, in terms of the user experience the changes over Fedora 6 are pretty minimal. The most notable features are the new Fedora default theme with its blue folders, and the advent of Fast User Switching à la Windows XP, Vista and OS X.
Like OS X, a "User Switcher" option appears in the Notification Area on the desktop next to the clock. Or, at least it should. I upgraded my previous installation of FC6 to Fedora 7 so that I could keep my home folder and settings (and all the work I'd done with Evolution.) The "User Switcher" does not appear in my upgraded desktop the Notification Area, although it does appear on the desktops of any new users I create. This isn't really a problem for me, and I haven't spent any time investigating.
Upgrading was easy. The biggest problem I had was that GRUB (the Linux boot loader) insisted on trying to boot FC6 - which no longer existed. I could hit a key to choose Fedora 7 from the menu, but I usually forgot. The answer was to edit the /boot/grub/menu.lst file and set the "default" value to zero so that GRUB would boot the first option listed (Fedora 7) rather than FC6. I suppose I could just have deleted the FC6 option altogether, but I was worried about screwing things up and not being able to boot at all...
Other than that, I had to rebuild my MadWifi wireless driver so that it would work with the new kernel, and - strangely - I had to reinstall the Java runtime. But that was it.
I continue to be very impressed with the Linux OS. My feeling about Linux "office" applications is less unequivocal. Fedora 7 comes with OpenOffice 2.2. Although OpenOffice applications are perfectly practical, because they are imitations of Microsoft Office applications you cannot help but compare them to the original: and if you do that, they are always going to fall short; they are always going to look and feel less slick and more clunky. I did download StarOffice, the paid-for version of OpenOffice from Sun. My advice would be don't bother. These is no difference in terms of functionality as far I could tell. StarOffice is supported, of course, but other than that there seems no reason to purchase.
Despite my misgivings about OpenOffice, and despite my frustrations with Evolution, I'm using Fedora as my laptop OS. Since installing Linux on an old Toshiba laptop about three weeks ago, I've only gone back to my Vista laptop once.