2011 Linux Graphics Survey Results
When it comes to display configuration, most are using a graphical utility (such as the RandR-driven utilities offered by the KDE and GNOME desktops or NVIDIA's nvidia-settings and the AMD Catalyst Control Center). There are still lots of people having to rely upon manually modifying the xorg.conf to take advantage of their graphics driver's available features.
Most users are still running a single display. For those using multiple displays, using a RandR configuration is more popular than Xinerama.
Most of the Phoronix respondents prefer an open-source video driver to a closed-source alternative. Preferring an open-source driver was twelve times more common, but there is still a large chunk of individuals that are not concerned whether the driver is open or closed-source, they likely just want their hardware to work as they expect it to.