Motorola’s Xoom tablet computer went on sale in the U.S. on Thursday, amidst positive reviews that labelled the device as the most powerful rival yet to Apple’s iPad.

Apple sparked the tablet computer craze last April with the iPad, and has since sold 15 million of the devices. It is expected to launch a second-generation iPad at a media event slated for March 2 in San Francisco.

Though companies like Samsung and Dell have tried to respond with tablets of their own based on Google’s Android operating system, the Xoom is the first tablet to feature the latest Android version, Honeycomb, which is optimised for tablets as opposed to smartphones.

The Xoom is roughly the same size as the iPad, and costs about the same for a similarly spec’d version, though buyers who opt for an iPad with limited memory and restricted to wi-fi connections can save hundreds of dollars.

The Xoom has slightly higher screen resolution than the iPad, and boasts front and rear facing cameras for picture-taking and video conferencing. Powering the device is a dual core 1GHZ processed with 1GB of RAM, and battery life is assessed at 10 hours.

Nevertheless, the consensus among established reviewers is that the device is a worthy competitor to the iPad.

“Both Motorola’s hardware and Google’s new software are impressive and I believe the Xoom beats the first-generation iPad in certain respects, though it lags in others,” noted Walt Mossberg in the Wall Street Journal. “As much as I like the Xoom and Honeycomb, I’d advise consumers to wait to see what Apple has up its sleeve next before committing to a higher price for the Motorola product.”

Engadget’s Joshua Topolsky said that the Xoom’s ability to multi-task gave it a key advantage over the iPad, but that the device still lacks polish. “Honeycomb and the Xoom are spectacular — unfortunately they’re a spectacular work in progress,” he noted.

MSNBC’s Wilson Rothman said the Xoom was a “worthy competitor” to the iPad and would only gain momentum as the price dropped and more apps became available. However he criticized both the screen and the body for being less scuff-proof than the iPad’s.

Like Mossberg, Rothman said potential purchasers might like to wait to see what other tablets come out in the coming few months. Not only may they prefer the iPad 2, both LG and Samsung have new Android tablets set to launch soon, while Hewlett-Packard and Research in Motion will both debut tablets based on their proprietary operating systems.

Keywords: GoogleAndroidHoneycombApple