The positive take from one of the most influential reviewers in tech journalism will help offset concerns about how user-friendly the scanner is. Fingerprint technology has been incorporated in laptops and phones in the past but proved notoriously unreliable.

The fingerprint-scanner on the phone has been hailed as a first step toward realizing the full potential for biometrics in personal electronics, heightening security for applications like banking and shopping while doing away with multiple passwords.

Mossberg wrote that the sensor built into the "home" button never failed to recognize his prints. At times however, the gadget would inexplicably prompt him for a password when swiping a finger to make purchases, which he blamed on a bug.

Re-tooled iOS7 mobile software, a better camera, a more useful voice-activated "Siri" personal digital assistant and a faster processor combined to make the iPhone 5S the best smartphone on the market, he added.

However, he argued that owners of the previous-generation iPhone 5 may not have a compelling reason to buy the latest device unless they specifically wanted the fingerprint reader.

The review did not cover the cheaper iPhone 5C, which went on sale online on September 13 and has already drawn fire for being too costly to protect Apple's emerging market share against an assault from Samsung Electronics and other rivals.

Many industry analysts view the iPhone 5S and 5C as being modest improvements on the previous generation, reviving fears that Apple's most innovative days may be behind it. They said the mere fact of a fingerprint scanner was unlikely by itself to make the gadget a sure win in a crowded market.