I still use Opera 12.16 because of its bookmarks pane. I have over 9000 bookmarks. The Opera 20 bookmarks bar can handle that number of bookmarks (spread across two folders) but it's very slow, taking 12 seconds to display the bookmarks each time I open one of the folders. Opera 12.16 is instantaneous.
Also, I can't see any way of filtering/searching the bookmarks in Opera 20. I use the bookmarks quick find in Opera 12.16 all the time.
That having been said, I've started using Opera 20 as a secondary browser to handle the pages that don't render in Opera 12.16 well (eg the new Yahoo Mail). I'm looking forward to being able to ditch Opera 12.16 completely since it's having increasing problems with different web sites. The browsing experience is much better in Opera 20, I have almost no problems. If the bookmarks issue was fixed I'd ditch Opera 12.16 in a heartbeat.
9000 Ultimate you can make another Web Dictionary I guess Wow!! I would love to see them !