Although Firefox Mobile is still my favorite browser for the Nokia N900 and the stock MicroB browser is certainly no slouch either, I couldn't ignore the news that a preview build of Opera Mobile 10 for Maemo was released today.
The new browser began as a side project in the Opera Labs and reflects only about six weeks of work in its current state, so it has some known issues like no support for the on-screen keyboard or Flash and other plugins, no power management, and visible screen tearing while panning. Some of these wrinkles will be ironed out in future updates, while others won't; in Opera's words, it's "much more fun to add shiny new features rather than fixing boring old bugs."
I've been playing with Opera Mobile 10 on my N900 and am impressed by its depth. I still like Firefox Mobile better (I'm also a desktop Firefox user), but I wouldn't say that it's necessarily a better browser than Opera Mobile across the board. I find Firefox more intuitively designed with all of its browser controls accessible with left or right swipes across the screen, and I like its desktop features and the way it handles zoom, but Speed Dial and Opera Turbo are definitely compelling reasons to use Opera Mobile when not on WiFi.
I don't find Turbo useful when I am on WiFi, which is actually all the time since I don't have a SIM in my N900, because I'd rather wait a few extra seconds to get better image quality, but that's just a personal preference. Pages load fairly quickly and render well, but zooming is a little tedious in that it's "locked" into whatever level is chosen in the settings menu. For some sites, 140% is great while other sites are easier on the eyes at, say, 160%. The default is set at 200%, which is way too big for me and cuts off images more than I can stand (an issue that many mobile browsers have).
I won't be ditching Firefox Mobile for Opera Mobile 10 on my N900, but the browser will definitely be a permanent resident in my program menu.
You can download Opera Mobile 10 using the default browser on your Nokia N800, N810, or N900.