The main thing that concerns me about taking on an update of my 2012 iMac to 10.9 Mavericks, is the potential loss of Force Feedback when playing racing games (e.g. DiRT 2 and other Feral ports) with my Logitech Momo Force wheel. I manually added the LogitechForceFeedback kernel extension (as suggested by other posts on this forum) awhile back, and have been thrilled by its ability to preserve the responsiveness and interactivity of the wheel with the games I love. Has anyone done the upgrade to Mavericks and tested their Logitech racing wheel after? Is the .kext deleted and needs to be re-installed? Is Force Feedback preserved?