Apple Inc.'s (AAPL) iPhone won a strong endorsement from a key technology reviewer on Tuesday when the Wall Street Journal's Walter Mossberg called it a "beautiful, breakthrough" device.

"Our verdict is that, despite some flaws and feature omissions, the iPhone is, on balance, a beautiful and breakthrough handheld computer," Mossberg said in a review on WSJ.com.

Mossberg, the Journal's chief technology columnist for more than 15 years, is widely regarded as the most influential judge of new gadgets, software and services, and his pronouncements can strongly affect how a product is received.

• Click here to read Mossberg's review.

The iPhone goes on sale on June 29 in two models costing $500 and $600 depending on memory capacity. It requires a two-year service contract with AT&T Inc. (T ) running at least $60 a month.

New York Times (NYT) technology writer David Pogue also weighed in with a largely positive review saying that the iPhone lived up to most of its considerable hype, even if it did fall short in some areas.

• Click here to read Pogue's review.

Shares in Apple rose $1.15, or 1 percent, in extended trading after the reviews were published. The stock fell 2.2 percent in regular trading to close at $119.65.

Mossberg said the absence of a physical keyboard, cited by critics as a potential weak spot that could dampen sales among power users who use handheld devices to write a lot of e-mail, turned out to be a "non-issue."

• Click here for FOXNews.com's Personal Technology Center.

The iPhone software "sets a new bar" for smart phones that add e-mail, Web access and personal organizer functions to a handset, Mossberg wrote.

"Its clever finger-touch interface, which dispenses with a stylus and most buttons, works well, though it sometimes adds steps to common functions," Mossberg wrote.

Pogue said the phone's e-mail, voicemail and Web browsing features were excellent, while shortcomings included lack of additional memory and non-Apple programs.

"But even in version 1.0, the iPhone is still the most sophisticated, outlook-changing piece of electronics to come along in years," Pogue wrote.

The biggest complaints were reserved for AT&T.

Mossberg said the quality of voice calls was good but not great, while Pogue took issue with the "excruciatingly slow" data network.

Mossberg said other drawbacks were the lack of a removable battery, lack of a way to search the phone's contents and lack of commonly used methods to edit or change a document's text.

Both reviewers agreed that the existence of only one hardware button, while stylish and simple, sometimes made it more difficult to place calls or control music playback compared to other devices.

"Expectations for the iPhone have been so high that it can't possibly meet them all," Mossberg wrote. "But, despite its network limitations, the iPhone is a whole new experience and a pleasure to use."