I am having a K750i which was one of the last lots of the model, company ceased production of this model. I still do not feel for a change since I do not see any huge advantagein the latest phones (other than 3G models).
All the features like camera with most of features found only in standalone camera(with flash), Mp3 player with mega bass, fast interface, long battery back up, easy messaging, and compact design are top class.
This phone had received lots of awards world wide including best camera phone award and placed sony Ericsson in top selling slots.