Auto reconnect download.
I never use Opera to download any files (except images). Why? Because downloading using Opera is like watching tv. Left it for a while, or if the Internet connection suddenly cut off, could fail.
UC Browser has this feature, and I can leaving the downloaded files and go to sleep.

Slide to remove in save pages menu.
Hold and delete? Not again! Too time consuming. Must be made as the bookmarks menu.
I suggested the above features but actually now I'm using Opera Mini version 8.0.1807.x and have no plan to update before these features change:

Hold on a link to open.
This view is very ugly to me. Too large and cover the screen. The old Opera is more unsightly (http://i.imgur.com/jc2WDSj.png)

Please bring back the Switch between windows menu like before.
In the current version, this feature is not efficient. I try to open 20 tabs, switching to another tab, and close it. And I'm sure the old version better and more efficient (http://i.imgur.com/2TnVq67.png)