I downloaded Fedora 12 yesterday, right after it came out. I have a laptop solely for testing distros, so I never have to worry about the risk implied in installing a new OS.
I just spent a few minutes installing Fedora 12, so I can´t provide a thorough review, that will come later. This is just about the first minutes with it.
I downloaded the ISO file from the distrowatch.com release entry, using the torrent file (always recommended, as it will most probably be faster than the actual download, and you contribute to not overload the download mirrors).
Booting from the Live CD allows for a first preview of what you are in for. The initial screen is very similar to the one used in Leonidas. Once again, the booting process is very smooth, aesthetically tasty. The transition from one screen to the next is very smooth, no plain text screens in sight.
The installation wizard has not changed much since leonidas. It is not as professionally looking as the one in OpenSuSE, but looks good enough. The partition section seemed revamped, clearer and easier. just for the sake of trying, I wanted to use the encryption option on my hard drive. I wanted to compare how an encrypted machine would perform against a standard, non-encrypted one. Installation completed pretty quickly, with no errors nor warnings.
Upon restart, I was prompted to enter the passphrase I had chosen for the encryption process. The booting process didn´t feel slow whatsoever, I was very pleasantly surprised. I am not sure if it is down to the fact that it is a brand new installation, but Fedora booted very quickly, perhaps even quicker than my Karmic machine. Considering that my test machine is an old laptop, that was very impressive.
The login screen has been updated, and it was a pleasant surprise. Once you enter your credentials, another beautiful screen shows up, with a nice loading progress animation. Very good looks throughout.
Once in the desktop, it´s all the usual Fedora goodies, plus some more I am yet to find. Using Yum is always nice. I like the application. It does exactly what it is supposed to do and does it very well!
One of the things I love about Fedora is using the latest of every application. KDE 4.3.3 looks great and my feeling is that it keeps improving performance. The KDE desktop now feels almost as responsive as GNOME. GREAT!
All in all, I think Constantine is the best Fedora release ever. I still need more time to be able to confirm such a bold statement, but I think I am right!