Good support for RSS, results that look useful, multimedia options, AJAX, date and relevance variables. The downsides are that there doesn't appear to be a FireFox plug-in yet, no support for tagging or other user applied metadata and a widget that only works with TypePad. That it's not based entirely on inbound links and doesn't support tags means that the algorithm really takes a different approach.
Speed test and other links after the jump.
Mike Arrington likes it and has a longer review. He's also got an hour long podcast interview with the company's CEO. (Update: Just listened to this podcast, it's worth an hour of your time if you have a dog to walk. The middle gets stale but the part about tagging is at the end. The whole thing is pretty darned good.) Om Malik has financial background. Steve Rubel likes it but says the true test will be speed vs. Technorati.
On speed: It's been added to GrabPERF, the blog pageload testing engine recently welcomed into the Technorati infrastructure. Here's initial results, Technorati in green and Sphere in brown. Click to view full size, up to the hour on the GrabPERF site.
Stephen Baker at Bizweek points out that Sphere is set up to rank longer posts higher. Sorry Dave. Not sure how I feel about results based on a mystery relevance algorithm that favors long posts, though slow as Technorati minus the downtime of Technorati is good enough for me.
