I'm giving serious thought to making Slimjet my main browser. I have used Opera for years, but not the current Chrome-based version - I'm still on 12.17.
One of the things I like about Opera is the ability customize the popup menus. I have one shortcut I use often, whereby I right-click on an image and open in the external viewer of my choice.
It would be great if custom menus were available in Slimjet, or lacking that, that an external viewer function was baked in.
The other thing I would miss is the onboard mail and feed client. But that's probably too much to ask for.