The advantage to me is that I sometimes use a new browser and lose these settings. Also for defining my own, I seriously haven't found a search that isn't already in DDG. Maybe back in the old days when you wanted a search box from a specific forum (though the site: operator usually works better imvho).

I was totally with you on Opera in 2002, however :) All the way until they dumped their own engine and lost many of their unique features. It was still kinda fun to use last time I installed it though. But it also feels just like Chromium with some stuff tacked on.