Whatsapp vs Blackberry Messenger. Which is better ???

With the release of Blackberry Messenger for Android phones (Version 4.0 and above), many people who have android phones versions less than 4.0 have been complaining of being marginalized by Blackberry. They simply cannot understand why BBM would not be made to work on their phones. I have done a critical analysis of Whatsapp and BBM. As for me the better of the two is