As a frontline helpdesk worker at a corporation that deployed hundreds of Blackberrys, I can assure you that the users frequently cared a great deal about the crappy UI of the Blackberry OS. When I left, the MIS (yes, we were that old-school) department were beginning to research moving away from RIM because their end-user devices were consuming too much of our helpdesk resources. And because the executives, who all had iPhones, came to us and asked the question why we couldn't provide them a solution that worked as well as an iPhone's email.