Apple Inc's iPad scored well on battery life and ease of use in its first reviews, but it will not obliterate the laptop computer market yet, according to The New York Times and Wall Street Journal.

Reviewers at both papers said the tablet computer, which goes on sale Saturday, works nicely for Web surfing or using media such as video and books, but it may appeal less to people who need laptops for more heavy-duty chores.

The iPad won largely upbeat reviews from other blogs, newspapers and magazines, including USA Today, the Houston Chronicle, PC Magazine and Newsweek, while so-called tear-down firms are preparing to take apart the gadget on Saturday for an even more detailed look inside.

Apple shares, which have been on a run ahead of the iPad launch in hopes it will be a hit, closed up 97 cents at $235.97 on Nasdaq Thursday afternoon.

Even if the device launch goes well on Saturday, there is a good chance its shares will trade down the week after because they had gained ground ahead of the launch, analysts said.

These stocks like Apple tend to trade up into events and trade down after, said Hudson Square Research analyst Daniel Ernst.

This would likely be temporary as the shares have more room to rise because Apple's valuation does not reflect that its earnings growth is about 10 times economic growth, he added.

The Journal's Walt Mossberg -- one of the most closely followed tech columnists -- said he prefers the iPad as an e-reader to the popular Kindle e-reader from Inc. Amazon shares closed down $3.96, or almost 3 percent, at $131.81 on the Nasdaq on Thursday.

David Pogue from The New York Times said the device's 1.5 pound weight is too heavy for reading compared with Kindle's 10 ounces. You can't read well in direct sunlight and you can't read books from the Apple bookstore on any other machine, not even a Mac or iPhone, he wrote.

Both reviewers were impressed with the gadget's battery life because it lasted longer than Apple's claim of 10 hours.

Pogue said he was able to use the device for 12 hours before it needed a charge, while Mossberg said iPad withstood 11 hours and 28 minutes of continuous use.

The device could only replace laptops for a certain kind of computer buyer, the reviewers said.

If you're mainly a Web surfer, note-taker, social-networker and emailer, and a consumer of photos, videos, books, periodicals and music... this could be for you, Mossberg said.

If you need to create or edit giant spreadsheets or long documents, or you have elaborate systems for organizing email, or need to perform video chats, the iPad isn't going to cut it as your go-to device, he wrote.

Pogue, who wrote a review for techies and one for everybody else, highlighted shortcomings versus laptops.

The bottom line is that you can get a laptop for much less money with a full keyboard, DVD drive, USB jacks, camera-card slot, camera, the works, he wrote.

Mossberg said the device was wicked fast, but had annoying limitations.

For instance, the email program lacks the ability to create local folders or rules for auto-sorting messages, and it doesn't allow group addressing. The browser lacks tabs. And the Wi-Fi-only version lacks GPS, he said.

Both noted iPad's support for the popular Flash video technology and questioned consumers' willingness to carry another device along with their laptop and phone.

If people see the iPad mainly as an extra device to carry around, it will likely have limited appeal, Mossberg said.

But they admired iPad's speed and ease of use.

The iPad is so fast and light, the multi-touch screen so bright and responsive, the software so easy to navigate, that it really does qualify as a new category of gadget, Pogue said, adding it would appeal to less tech-savvy users.

Some have suggested it might make a good goof-proof computer for technophobes, the aged and the young; they're absolutely right, he said.

Another influential reviewer, Edward Baig at USA Today, summed up his thoughts on the iPad by proclaiming it a winner in his latest column.

Apple has pretty much nailed it with this first iPad, though there's certainly room for improvement. Nearly three years after making a splash with the iPhone, Apple has delivered another impressive product that largely lives up to the hype, Baig wrote.

(Reporting by Sinead Carew and Paul Thomasch; editing by Ian Geoghegan, Andre Grenon and Robert MacMillan)