for what happens when this gap arises. Anybody who says that consumers always get what they want in Agile environments is lying. As an old and trusted mentor used to say to me, s**t happens, it is how you deal with it that defines you.
Having a ScrumMaster and creating time-boxed iterations and burndown charts is an approach to software development and it cannot be proven to be any more or any less efficient than other approaches to building robust software. There are enough successful exponents of this approach however to demonstrate that it can be extremely effective. However, if the consumer is not part of the Agile environment or does not understand the true purpose of the Agile methodology and the way it is rooted as a solution to the real life truth about the gap, then all you have taken are elements of a methodology and not the methodology itself. There is nothing wrong with what you are doing but you are only being honest.