I may misunderstand the above thread. However, having thought I'd give Opera a go (I'm trying to find a decent sychronisation facility between several computers and Opera's Synchronise seems highly spoken of), I now discover that I cannot import my old Firefox bookmarks (hundreds, like the individual above). If the answer is that I have to import them individually, that seems to rather defeat the point of me coming across to Opera.
So, in case you care, you've just lost me back to bloody Firefox!