I use opera for some things (reddit, news.yc, webcomics, games), elinks for others (mostly forums), and vary between the two for research and other things.

I like how easy it is to navigate with the keyboard in elinks (though the default setup is awful, IIRC). I've set up opera to have many of the same bindings, but navigation in particular just doesn't work as well. Partly that's because there's no grid, but I think it's also just not as well designed.

I also like how elinks knows what the 'page down' function means. It either scrolls a page down (if I'm not at/below the bottom) or it doesn't (if I am). All other browsers in my experience think the bottom of the page is more important than my knowing where to start reading from.

A plus for opera is that I've actually worked out how to script it.