albo - 3:30 am on Nov 24, 2010 (gmt 0)
@tedster, perhaps it is peculiar to MacOSX, but it has happened no matter whether I pursue a fresh install or a "prompted" upgrade (Opera says, "a new version is available: do you want to install?") Also, upon attempted bookmark import, I'm presented with a Finder window, and prompted to search for a file containing bookmarks. This, I consider not to be user-friendly or "forward-thinking."
Insofar as CSS support is concerned, though Webkit uses proprietary tags (-webkit-...) in many instances, its support of advanced CSS properties equals or exceeds that of Opera, in my experience.
[Edit: I don't recall this sort of problem having happened on any browser I've upgraded since 2003 on Windows or MacOSX. Although Camino on MacOSX has a hard time importing bookmarks.]