This is only the second day of the general availability of Fedora 23, so this is not a full-on review. It is just a quick look at what I have experienced so far.
I was so excited to try Fedora 23 that I broke my own rules and installed it directly on my primary workstation without so much as a test in a VM.
Yes, I was able to upgrade from Fedora 21 to Fedora 23. I have not had a successful upgrade in years and have had to resort to complete reinstallations — while saving home directory data, of course. The old fedup program never worked for me.
The network-based dnf system upgrade procedures worked very well with only one minor glitch.
I installed the dnf upgrade plugin, used the dnf system-upgrade download command to download the packages required to perform the upgrade on my system, and then rebooted to perform the upgrade.
The only problem I had was that the download procedure did not download or install the Fedora 23 public signing key. I installed that manually and the rest of the procedure worked just fine.
All in all, it took a little under 3 hours to perform the upgrade, in large part because I have a lot of things installed for testing purposes.
In my look at Fedora 22, I was very critical of the state of the Plasma 5 desktop environment because it was far from complete and there were many issues that prevented me from doing the daily work that I required.
Plasma 5 in Fedora 23 is far more complete and well polished. It still has a few minor rough edges, but everything works as I expect it to. I still do not care much for the default Breeze icon set, but at least now I can change to a different set using the System Settings. Despite that, I am using the default set so I can spend enough time to give them a fair test.
Too Early For Conclusions
It is way too early for any final conclusions about Fedora 23. However my brief experience so far leads me to predict that this will be an excellent release of this staple desktop OS. And so far I have only installed the desktop version and not the server version.
I will try to post a more complete review in the News and Reviews section of this web site when I have more experience with it and some time available to do so.