No problems upgrading to iPhoto 11 for me. In fact, it recovered about 20 photos I thought I had lost from an import a few weeks ago. I'm loving the 'Places" slideshow theme. I sent feedback to Apple asking for more control over the labels it displays, but overall its truly 'magical.'
fan, but too many Apple apps are launched before they are ready these days. Remember what a disaster Aperture 3 was?! Do these developers not actually use these apps on their own machines before they are sent out to market?? Keep this up Apple, and your fans will be running out the door.