My main machine(s) are now all running Fedora 15, complete with the Gnome 3 desktop interface. After a few niggles to get things running (getting latest nvidia drivers for one machine, issues with NTFS formatted disk on another) I can happily say if feels quicker and more responsive than my Fedora 14 experience and that was pretty good.
Installed on Fedora 15 launch day (yesterday, 25 May 2011) I've not pushed things yet but a few things to note:
Gnome 3 is going to take some getting used to! Everything seems to be hidden away behing the (prettily animated) menu system. Ok, this keeps things tidy, but finding an application I want can be frustrating as it seems to involve more clicks with the mouse than in Gnome 2. I've not yet found a real way to customise menus either except for adding icons to favourites meaning they appear in a single list on the left after clicking on the 'Activities' button of the panel.
Talking of the panel (the bar at the top of the screen that houses the clock and open programs), it seems I no longer have an "add to panel" option. So I can't easily add the system monitor tool to the top of my desktop as I like to do.
Not having an option to minimise windows seems odd too. I don't think I used it much before, I tend to alt-tab between windows, but now I have noticed the minimise button has gone I miss it for some inexplicable reason!
Libre Office is now the default office suite in Fedora from Fedora 15 onwards. Libre Office was forked from Open Office when Oracle (new Java owners) announced they wouldn't be actively developing it further. In the quick half hour of playing with a spreadsheet that I've had with Libre Office so far, I have been impressed with it's speed and feel compared to Open Office it replaces.
However it does seem in the spreadsheet I had opened I am going to have to work out all those date calculations again as a lot of the formulae that worked in Open Office seem to be less than functional in Libre Office. I can only assume that some syntax has changed slightly.
Fedora 15 conclusion after a few hours
Fedora 15 has been on my main machine and in use for only a few hours and so far feelings are mixed. The move to Gnome 3 means a big change in the way you interact with your desktop, the jury is out IMO on whether this is for the better or worse.
Having said that, Microsoft took a bold step when they introduced the 'start' button menu system in Windows 95 and that seems to have worked out ok.
Speed and responsiveness of the machine feels much better than 14 and I didn't have any significant complaints there anyway. Fedora 15 certainly looks a lot better than earlier versions.