RIM's PlayBook tablet bombed with influential technology reviewers who called the iPad competitor a rushed job that won't even provide RIM's vaunted email service unless it's hooked up to a BlackBerry.

The poor initial response to a device the company hopes will get it onboard the tablet computing explosion overshadowed a splashy coming-out party in New York Thursday evening, where co-CEOs Jim Balsillie and Mike Lazaridis drummed up the gadget's attractiveness with corporate users.

There was little mention of the stinging reviews only hours before.

RIM has just shipped a BlackBerry product that cannot do email. It must be skating season in hell, New York Times' David Pogue wrote in a review published on Thursday.

Research In Motion built its reputation on a BlackBerry email service that it says is so secure that it can't bow to government requests to tap messages, winning high-profile customers in business, defense and politics before branching out to a wider consumer market.

But the PlayBook, which hits North American store shelves on Tuesday, offers that secure service only in tandem with a BlackBerry. RIM says secure email and other key services will come later, not at launch.

I got the strong impression RIM is scrambling to get the product to market, Walt Mossberg, the widely followed business and consumer technology critic, wrote in a Wall Street Journal article headlined PlayBook: a tablet with a case of codependency.

The pessimism of the reviews seemed to hit RIM's often volatile shares, which fell 1.7 percent to $53.92 on the Nasdaq on Thursday, the lowest closing price since Oct 25. It fell a further 1.1 percent in after-hours trading.

RIM's 7-inch WiFi-only device is priced identically to Apple's 10-inch market leader and faces tough me-too competition from a slew of devices running Google's Android software.

It is a first step in a major product overhaul intended to reinvigorate RIM's fortunes. But the lukewarm initial reception, coupled with an outburst from Lazaridis that went viral on Youtube, cast a shadow over the coming-out party.

IMPRESSED?

Most reviewers have been impressed by the PlayBook's well-documented capability to handle Flash websites and its ability to show one high-definition image -- a movie, for instance -- on a connected TV, while doing something else on its own screen. Those are two things the iPad cannot do.

But reviewers paid more attention to what the PlayBook can't do.

The PlayBook needs a smartphone to access a cellular network and a BlackBerry to tap into RIM's popular BlackBerry Messenger chat platform or get secure emails.

The PlayBook's secure Bluetooth link with the BlackBerry mirrors a user's existing BlackBerry applications, negating corporate worries about leaking confidential information.

It was a question on security, and Indian government demands for access to the information that the BlackBerry protects, that co-founder Lazaridis took umbrage with during a BBC interview this week.

That's not fair, this is a national security issue, he said before ordering the camera off.

On Thursday evening, Lazaridis gamely showed off the PlayBook's features to Reuters, calling the device -- which comes pre-loaded with the venerable Tetris game -- the ultimate gaming machine partly because it can be hooked up to a TV.

But the gadget's camera app failed in the middle of the demo.

I broke the camera app, the rendering isn't working. Bring me a new one,' he said to a nearby media relations executive.

RIM says the PlayBook and its brand-new QNX-based platform will launch with around 3,000 apps, the third-party tools that have helped make Apple's iPhone and iPad so successful.

That number will grow in coming months as RIM adds support for Android apps and those available on its smartphones.

The iPad has a library of more than 65,000 apps.

It's too little for Mossberg, even though RIM plans to add a video-chat app soon and key email and personal organizer features, plus cellular connection, later in the year.

Until then, I can't recommend the PlayBook over a fully standalone tablet, except possibly for folks whose BlackBerrys never leave their sides, he wrote.

In other critical comments, tech websites Boy Genius Report and Engadget zoomed in on what may at first glance appear trifling: a small and hard to operate power button.

It's impossible to find by feel and, once located, difficult to activate, Engadget said.

Reviewers also fretted that, days ahead of a launch that will define RIM's standing in the tablet market, the company was still pushing out software updates to fix bugs.

The PlayBook of today is considerably better than the PlayBook of yesterday, which also was a big step forward from the one we were reviewing two days before that, Engadget said.

(Editing by Peter Galloway, Janet Guttsman and Bernard Orr)