I've never experienced an answered prayer. But I've never truly prayed in faith either. Even as a jw elder, I was never really sure that God answered prayers.
Part of the problem is that either way, God has an out, as it were, because we are told (and not just by the Watchtower) that God doesn't necessrily answer all prayers, even those directed to him in faith. He may wait, or deem it better for us that the prayer isn't answered.
Well, if the answer is no, why aren't we told that? Instead, we are asked to somehow presume that when nothing happens, that means God has either said No or that he wants us to wait. But we have no way of knowing.
A parent doesn't do that to his children. In Matthew, Jesus compared God's response to our requests to that of a parent "who knows how to give good gifts to his children". But if, as a parent, the answer is no, the parent will say No. The child is at least getting an answer.
Imagine asking a parent for something and not getting any answer back. Silence. Not even a "we'll wait and see".
That's part of my problem with the whole thing. We don't know where we really stand.