I installed Fedora 20 on my laptop yesterday, and wanted to share some first impressions. The obvious place to start is with the installer; this is the first thing that any new user will experience when installing the operating system. I've written several installers myself (including several versions of the FreeDOS operating system installer) so I know first-hand that it's important to get this right for usability.
ZDNet has a hands-on walkthrough of Fedora 20's "Anaconda" installer. I'll point you to them for screenshots.
Most operating system install programs try to streamline the install process, and use a "procedural" method. That is, the installer walks you through each of the steps; you answer a few questions (preferred language, time zone, etc) then the operating system just seems to install itself. Fedora 20's installer uses a "hub and spoke" model for the install process. I find this interesting for some parts of the installation, but overall it gives the impression that you need to know something extra before you can do the installation.
My biggest gripe with the Fedora 20 installer is the "Installation Destination" section. This is where you set up the hard drive where you will install Fedora. I previously had installed Fedora 19 Xfce on this laptop, so all I wanted to do was to install overtop what I had. I was totally okay with losing my existing data; I had already backed up the few files I wanted to keep. But it just didn't seem obvious how to do that.
I went into this section, did my thing, thought it didn't work, went back into the section, re-did my disk setup, saved … before I finally decided that it was okay. This from someone who has been tinkering with Linux of different flavors since 1993. I know what I'm doing, but I really doubted myself when trying to do something as straightforward as re-installing Linux on this laptop. (See ZDNet's screenshot for this step.)
I will say that Fedora gets it right when the system is installing Linux for you. While the installation is happening in the background, you can also set up your login account and root password. (See ZDNet's screenshot for this step.) And it doesn't let you continue until you've done that, so even if you walked away and ignored the screen, you'll still have to complete those two steps before you finish. That's about the only time the Fedora 20 "hub and spoke" install process really feels natural.
I have a few other minor issues with the installer, but these are focused mainly on visual details and presentation style, not so much about "usability."