The virtual keyboard of Opera is crappy... and the browser is landscape only. As a result, I almost never use it.

In the beginning I used the built-in browser because I rather liked its simplicity and cleanness, its speed, and the way it formats websites, and the ability to add icons to the main app screen suits me well because it treats web apps the same as real apps.

But I've since started to use Fennec a lot more - not because it's inherently so much better (it has its issues too and this version was not designed specifically for Harmattan) but because mobile sites, I've learned, generally suck. For some reason site designers tend to dumb down their sites for mobile, and generally have less content available on the mobile sites. Really bugs me, so I've taken to going to the desktop sites now, which I can only do with Fennec.