When I moved to Opera full-time as my browser of choice the feature I missed the most was Firefox’s Find As You Type. This allowed you to find text on the current page simply by typing it in and without having to call up a clunky Find box. While it was rather hit and miss, it is a great feature.
Opera has a slash
While Opera doesn’t have Find As You Type it does have a handy find shortcut that works in very nearly the same way. Simply press forward slash (/) and type in the text you are looking for. You can press F3 in the normal way to jump to the next instance and all the instances are highlighted for you. Yay!