I also used Opera because of the UI, but for a different reason. You could move around and change the entire UI and all the keybindings.

For example, I have all my tabs on the left side with thumbnails. Since my screen is widescreen, having the tabs on the left makes a lot more sense than on top.

I also use the built-in Mail client as I really hate going to web pages to check my mail when my browser can aggregate multiple accounts into a single interface and notify me when I get email on any account.

I hope the new Opera supports the same type of customizable UI and mail client or I'll be stuck on 12.15 forever.

Dragonfly is just amazing... I can hardly live without it. That and the UI are the main reasons I use it.

And most people I talk to feel the same way (who use opera).

Erhm, have you tried vimperator/pentadactyl? You know, one of the projects that started this whole "let's bake Vim into the browser"-craze? (They didn't exactly start it, I think, but they sure made it popular.) I can distinctly remember a couple of years ago when I switched from Opera to Firefox precisely because of Vimperator, because it was impossible to replicate the experience fully within Opera. It is still impossible today: Pentadactyl (Vimperator's successor) is much more fully-featured than anything you can do in any other browser, because of Firefox' approach to plugins.

Yup, I have both installed in Firefox and use whichever one isn't broken by the most recent FF update.

FF has the best plugin system, there are some FF plugins like Ant (flash downloader) that have no counterpart on Chrome or Opera, and of course Firebug for web dev.

I tend to use FF, Chrome, and Chromium for web development, and Opera for browsing, and test on all four.

You can bind any action to any key you like in Opera, how did you fail to implement a vim-like keybinding scheme then?

It's not the binds. It's all of it, including stuff like buffer lists, programmability, marks (marks are so bloody important to me when reading long web pages. I'm seriously, seriously angered by the fact that PDF readers don't have them, and I might, one of these days, scratch my own itch and go hack them into evince or so.)

Opera doesn't even have a concept of marks. Never mind marks across browser windows, tabs, or even pages you don't have open. Also, I love the minimalistic interface: you only see a small status bar, and (optionally) a tab bar. You can even hide everything. You can't do that with Opera (at all.)

Vimperator and Pentadactyl actually give you a vim command line.