...if the experience that trascends subject & object is an experience of reality would it indicate anything about who/what we really are?
I think the experience can reveal a great deal about who or what we are, Robert. For instance, it can reveal that at the very least we are not merely or only our conscious awareness. By "conscious awareness" I mean consciousness, the self, the ego, the "I", or whatever else you might call it.
Yet, whatever conscious knowledge we get out of a mystical experience entirely depends on our skills at observation and analysis, along with whatever conscious knowledge we have to build an analysis on. In other words, gaining conscious knowledge from a mystical experience is little different than gaining conscious knowledge from a non-mystical experience. It is possible for Jones to be a better observer than Smith. It is possible for Smith to have better analytic skills than Jones. And it is possible for both Jones and Smith to lack the knowledge base of Klein. Observation, analysis, and conscious knowledge determine whatever new conscious knowledge we get from a mystical experience.
A closely related issue is how a mystical experience might transform us. Here, it is important to understand that we need not be consciously aware of our having learned anything from a mystical experience for us to have indeed learned something -- even have learned a great deal.
At first, that might seem counter-intuitive, but please consider the million or so things you know about this world that you are not consciously aware of knowing, and probably did not consciously learn. To take a simple case of something we did not consciously learn: Most of us can tell the difference between a fake smile and a genuine one even though we most likely didn't consciously learn the difference.
The main transformative effects of a mystical experience, then, are most likely based on what the experience unconsciously teaches us. And, after such an experience, we might find we have all sorts of intuitions about ourselves, others, and the world that we did not seem to possess prior to the experience. Whether we listen to those intuitions is, of course, another matter.