I ran all the updates on mid-2011 iMac and seem to have no problems thankfully.
Just disappointed that although iPhoto will now open my Aperture library, it doesn't display the folder structure I built to organize our photos. IPhoto Just shows page after page of events. Messy. But then why open iPhoto anyway.
So glad I purchased a second hard drive for weekly SuperDuper clones.
iMac, iPhone, iPad, iPod, Apple TV, Airport Express, Bell FibreOp.