We recently developed this so speaking from some experience http://appworld.blackberry.com/webstore/content/28561
The bb version took far far longer than the equivalent iOS, simply because of other nonsense such as the pain in the signing process (isthesigningserverdown.com the fact it exists tells you all you need to know). Random exceptions being thrown that have no useful meaning and of course the joy of RAPC throwing errors such as "CreateProcess error=87, Parameter is incorrect" which we eventually found was due to the classpath being too long for RAPC to handle
However once complete the application it is something we are very proud of!