A user posting on Google's blog under the name "sebastian" said the Caffeine test page provided 7,130 results on a particular query, compared to 803 results on the old page. "Results are not the same in first three pages but more relevant. GREAT JOB!" wrote "sebastian".
Another said that Caffeine did a better job tracking social networking sites. "I've noticed more Twitter pages in the results with this version of Google," wrote "Holly". "Quite like having that—makes it easier to find people and companies," said "Holly".
User "maznetwork" said Caffeine delivered cleaner results overall. "Wow, the index is way more pertinent, less spam, more good Web sites. I'm tracking a lot of searches and see huge improvement in the quality of results," said the user.
The reviews weren't all positive, however. "Xomero" said Caffeine didn't load properly on his mobile device. "I'm trying to access on my Symbian phone, but the URL directs me to the URL with a '/m" at the end and that shows me a 403 error page," said "Xomero."
Google on Tuesday took the wraps off Caffeine in a blog post that caught most of the tech world off guard. Google engineers revealed that the company had been working for months on a "next generation" search architecture.
In their post, engineers Sitaram Iyer and Matt Cutts said Caffeine promises to "push the envelope on size, indexing speed, accuracy, comprehensiveness and other dimensions" of Internet search. The engineers provided few technical details about Caffeine but noted that the platform would function "under the hood" of Google's existing search pages.
Though little is known about Caffeine's inner workings, its launch comes amid an all out effort by Microsoft to dramatically improve its standing in the search market—where it's currently a distant third to Google.
Microsoft last month reached a partnership with number two player Yahoo, under which it will extend its new Bing search engine to all of Yahoo's Web properties. Microsoft also gained license to Yahoo's search patents and licenses, which represent technology Yahoo spent millions of dollars to develop.
Yahoo will keep most of the revenue generated by the deal, but the arrangement delivers unprecedented scope and scale for Microsoft's search engine.
Google did not state when it plans for formally launch its Caffeine architecture.
InformationWeek has published an in-depth report on why businesses shouldn't shrug off Google's upcoming Chrome OS.