Blackberry of iPhone: A competition from Twitter usage

In US mobile market, more than half of BlackBerry users intend to switch to the iconic iPhone as Wall Street experts pull the plug on RIM’s recovery plans. While I was reading some researched which compared iPhone and Blackberry  user habits, I came up a question in my mind. I wonder my blog reader choose which mobile device when they tweet ?

An example from my country ( Turkey) % 59 of twitter users prefer mobile devices to tweet.  When it comes to device selection, Turkish users prefer BB with a percentage of % 45 , on the other hand only % 27 iphone users prefer to tweet via their devices. Ok, I agree to type with qwerty keyboard, but is it enough for RIM company to survive in smartphone competition. I am looking forward your comments. Which smartphone do you prefer to tweet ? BB or iPhone ?