In the last day or so enabling layers.offmainthreadcomposition.enabled has made my Nightly unusable on Linux for me. The content of the page displays on load then scrolling on the page does not update until you get to the bottom of the page. Setting the OMTC pref to false makes Nightly useable. Working on a regression window. My current nightly is built from 15099ba111e8.
Screencast of the issue http://people.mozilla.org/~kbrosnan/tmp/1087080/example.webm