First they started with their idiotic versions numbering, then i got an awful stuttering while scrolling webpages and now it's also regularly locking up on my netbook. It was really a pretty hard decision but i just gave up on it now and switched to Chrome.
Though it didn't went without customizations. I had to install the following extensions to make it as close to Firefox as possible and to fulfull my needs:
Chrome Update Notifier Plus
Google Mail Checker
Google Reader Notifier
RSS Subscribtion Extension
Send from GMail
I still miss search engines syncing because i use many search engines with keywords and this is a must have. RSS feeds work pretty ok through Google Reader, GMail Checker is a bit twitchy but it works. Oh and mouse gestures are still a bit buggy. Especially since they don't even work on some pages where Opera's and Firefox's mouse gestures work everywhere without exception.
I hope Firefox will get fixed soon though, i still think it's a great browser. But i'll use Chrome for now until something goes horribly wrong here...