RIM’s BlackBerry PlayBook tablet has gone on sale in the US after months of teasing. However, a lack of buzz and poor reviews has stalled RIM’s plans to dominate the fierce market and tough competition.

The 7-inch tablet has gone on sale across the US at $499 for the 16GB version, $599 for the 32GB model and $699 for the 64GB offering.

But while opening sales figures aren’t yet known, reviewers in the US haven’t rated the device well; seemingly upset that it doesn’t have native email, a calendar or support for many of the apps people use on other devices like the Motorola Xoom or Apple’s iPad.

In fact, app support for many favourites is unlikely to be present on launch at all. Facebook, Twitter, Dropbox, Kindle and Google Maps are all missing, along with a majority of high profile iOS and Android apps.

RIM has said that it plans to address all these software issues with updates rolling out as quick as it can, and no doubt we will get more news on when, what, where, why and how at the company’s BlackBerry World event in May (Pocket-lint will be there). But the lack of overall excitement has forced many to rethink whether the wait was worth it.

That lack of support has meant that, for the time being, many are adopting the “wait and see” approach, rather than queuing to get their hands on the latest BlackBerry device. There's certainly been no Apple-esque queues or fans camping outside stores.

In addition, analysts polled by Reuters estimate RIM will sell about three million PlayBooks in 2011 compared to Apple’s projected 60 million sales.

However, it’s not all doom and gloom. Historically, RIM has never been one to benefit from launch hype - an experience that it’s learnt all too well in recent years.

And a customary teardown by the chaps at iFixit proves that the PlayBook has the hardware spec to take future upgrades, with it sporting a fast processor, two cameras (3-megapixel on the front and 5-megapixel on the back), and a digital 3-axis accelerometer for gaming.

The BlackBerry Torch smartphone, like the BlackBerry PlayBook, was also slammed in the US in early reviews, but that didn’t stop consumers flocking to buy the touchscreen slider after it transpired that early reviews were based on pre-launch software that was quickly fixed. The Torch is now one of RIMs most successful phones.

Certainly, it’s something that looks to be the case when the PlayBook comes to the UK in the coming weeks - our sources suggest the UK version will have been tweaked for the new market before launch.

Speaking of which, although RIM has yet to officially announce a UK launch date, it hasn’t stopped Phones 4 U starting to take pre-orders. It’s normally a good sign that things are starting to happen and should, in theory, mean that Brits don’t have long to wait.

RIM’s PlayBook isn’t dead on arrival as some have suggested, but it does have a lot of work to do to prove that it’s got what it takes to take on the market leader.