There's a bad surprise to see that under Opera 36, the quick cards search bar on the speed dial page has removed.
Effectively, that functionally it's very useful and gives users to see precisely their speed dial pages using a fast auto-showing speed dial cards when they write some word that matches with the url, or mainly when the matches is done using tags put on the title. The search was moved to URL Bar, there's good also to do a search of speed dial url using the bar, but it can consider that isn't practical, it makes confusions with a lot of others url's propositions, even if the speed dial icon is previewed, identifying the kind of url.
Quick cards speed dial search (Ctrl+F in speed dial page) was very useful on the oldest versions. In Opera >=36 this quick search is available only when people go into a folder in speed dial, limiting the search only on that folder. It's useful also, but considering a speed dial filled up of folders, there's less meaning. Folders is good to organize.
I hope that Opera developers thinks to restore this functionality, like before.