it's official...

I uninstalled Fennec this morning after trying one last time

With the responsiveness and functionality of the new Opera Mobile, I just couldn't see keeping Fennec on the n810 anymore.

Besides, I gained 30 mb of space by removing it.

Well, Fennec (I'm using nightly builds) is still better than anything I have tested on few heavy web pages that I use.
Opera starts faster and menus and everything works very smoothly but web pages don't render faster IMO (at least noticeably). Opera miss interprets my scrolling too often as zoom which is annoying. Also, sometimes Opera scrolls like crazy when I try to move one screen length forward (or backwards). And when Opera start loading some heavy web page, the web elements jump around a lot which makes reading in the beginning a bit harder.
But I got to admit that the speed and smoothness of scrolling is really good. This is just my observations after little test with Opera. I have to keep it installed and test it further

But Adblock and Weave are huge bonuses for Firefox which keeps it still as my number one browser on my N810.

If they can get FF to the snappiness of Opera Mobile, I'll be all over it, but I can't see dropping Opera for a while. It's much better IMO than any of the other browsers. While others have nice features, and some have the speed, Opera seems to have the whole package, and right off the bat too. I really hope that they continue to develop it, and so thankful they didn't forget the nxo! Don't forget that opera:config has some useful options to tweak!

And a major prtoblem of Opera that it displays some sites (Hotmail, etc. ) with the mobile sites only as the user agent cannot be changed.