With Opera's first two betas of its upcoming 10.0 browser, it came a long ways to closing the speed gap between it and Chrome/Safari.  In the popular SunSpider benchmark, though, the third Opera beta still lags behind Firefox 3.5.  Nonetheless, the third beta does offer noticeable speed increases, as well as new customizations.

The exciting thumbnail preview feature, similar to Aero Peek in Windows 7 and a canceled feature of Firefox 3.5, is now customizable and can appear to the right or left and on the top or bottom of the screen.  The browser's crash logger has been improved, as has the turbo mode, a feature which uses Opera's servers to compress data for faster browsing.

The new beta also features improved language support -- 38 languages are now supported.  Other popular features present in the other betas return, including inline spell checking, an integrated email client, and a web feed reader.  The browser also scores a perfect 100 on the challenging Acid3 test, thanks to its strong standards support.

Still, the browser does have its rough edges.  Security is rather poor, though much of Microsoft's protections (such as anti-phishing, and detecting malicious URLs) typically are not needed by more web savvy users (though you can't always count on your friends, family, or a significant other being as knowledgeable). 

Furthermore, some pages that have been designed around the Firefox/IE 8 duopoly may have minor quirks.  For example, dynamically resizing Office-like windows in blogs sometimes experience an odd glitch where they get stuck in an infinite downscroll when the typed text hits the bottom of the box (triggering a resize in Firefox).  Again, this probably isn't the fault of Opera or its rendering engine (Presto), but rather is an unfortunate inevitability of being a smaller player in the browser market.

Nonetheless, Opera 10.0 beta 3 seems a sign of good things to come.  With Opera a leading player in the smartphone browser market, and currently on the Nintendo Wii and Nintendo DSi, the company appears to be moving in the right direction.  And for experienced users, the new beta, like the last couple, is definitely worth taking for a ride.