Research In Motion's new Playbook tablet has received mixed reviews ahead of launch on April 19.

Overall, reviewers noted that:

1) New QNX OS is great, hardware is great, and user interface is great

2) Native email and calendar requires tethering;

3) Does not measure up to iPad 2.

We had expected/hoped for more positive reviews, especially regarding tethering as it does not require an additional data plan, Jefferies analyst Peter Misek wrote in a note to clients.

More than 60 million Blackberry users can pair it with their handset, or the Wi-Fi browsing is good on a standalone basis. Also, software upgrades will be coming to add stability, refine rough edges, and provide native email and calendaring.

The $499 PlayBook is launching April 19 at Best Buy and other retailers in the U.S. and Canada. Distribution will subsequently expand to 20,000 stores including AT&T, Verizon, and Sprint.

According to a survey conducted by RBC Capital Markets, 12 percent of BlackBerry users are planning to buy a PlayBook. This may affirm RIM's strategy of first focusing on its BlackBerry base.

Attractive features cited in PlayBook include Rich Browsing/Flash, personal email, Office integration and Android app compatibility.

Rather than offer 3G wireless or standalone email/PIM (calendar, contacts, etc.), the first-gen Wi-Fi PlayBook uses BlackBerry Bridge to securely view the users' BlackBerry email/PIM.

RIM may have done this to accelerate time-to-market, offering 3G connectivity via Bridge vs. delaying the launch for 3G/4G carrier certification (expected in the second half/calendar 2011).

Thus, while retail store checks show modest pre-orders, in our view uptake over the first 6 months (including 3G/4G, Android compatibility) may be a better measure of PlayBook's success, RBC Capital Markets analyst Mike Abramsky wrote in a note to clients.

Abramsky said the first-gen PlayBook is expected to differentiate on its performance, full web/Flash, state of the art hardware/display, multitasking, enterprise level security, and 7 portability.

While it may face early criticism for no 3G/4G, lack of standalone email/PIM, and limited apps, we expect these concerns will become non-issues with subsequent enhancements and second-gen versions, Abramsky said.

After a modest start, Playbook - once it launches 3G/4G versions and enhancements - is expected to garner growing uptake and help improve sentiment, the analyst said.