And here's why even in an experiential path you can't escape metaphysics! Francis Tiso remarked about this in his book about Tibetan Buddhism:
“Granted, in a nondualistic system, perceiver, act of perception, and the one perceived are considered unitary— a moment in a flow of perceptions. Perception, too, is linked to the notion of the perceivable attributes of a particular phenomenon. One of the ways to deconstruct the notion of a phenomenon’s “existence” is to argue that once the attributes are removed, there is no phenomenon. Thus, there is thought to be no need for a metaphysical substrate to which attributes might “adhere.” In any case, this is a classic Buddhist argument. Nevertheless, when an action takes place subsequent to a moment of perception, conditioned by that act of perception, even a nondualist system will have to acknowledge a flow of causality at least on the relative level. This analysis of course proves nothing, but it does suggest that the interpretation of a phenomenon depends on reflection, knowledge of what system we are using to interpret it with, and what intention we are advancing in our interpretation.”So who is correct? The mainstream interpretation of Nirvana for most Tibetan Buddhists fall into Nagarjuna’s Madhyamika (or Middle Way) camp. This philosophy is aligned with the Rangtong view that, “Everything—meaning all phenomena in all states—exist conventionally, or nominally, or provisionally, but not inherently. In other words, whatever exists, exists, or co-arises, interdependently with other phenomena. This dependent co-arising, or interconnected origination, is called “emptiness,” because it implies that whatever arises has no independent self-existence or self-nature; therefore its “essence” is emptiness” (L. Ron Gardner).
But are all things really reduced to emptiness?
Let's first acknowledge that 'emptiness' is an unfortunate word. Emptiness does not mean nothingness, but rather the recognition and direct experience of the true nature of the individual and world that is merely a representation. All such phenomena is ‘free from permanence and non-existence'.
When we see things as empty, there is an opening. Eventually, it all opens itself onto it-Self. We are no longer entangled with the contents of our consciousness. Yet, something remains.
Indian sage Shankara would often debate Buddhists around this issue, and hold to the idea that Brahman, not emptiness is Ultimate reality. For phenomena to have impermanence, something must remain the same. As such, there exists an all-pervading, spaceless substratum underlying phenomenal existence.
The Yogacara (or Mind-only) school of Buddhism, which arose subsequent to Madhyamika in India, likewise rejected Nagarjuna's metaphysics by emphasizing Consciousness as the Essence of all phenomena.
Ultimate reality is not dependent origination, but an uncaused cause. The Unmade, Unborn can not be an empty, essenceless, no-thing that creates something. Something must come from someThing, that is not a thing, but the Self-Existing, Self-Radiant Self-Awareness known as many things: Absolute, God, Tao.
The metaphysical implications are significant, since the transcendent allows us to have an ontological standard to order the good, true, and beautiful.
Self-evidently, Reality is real, and therefore I side with the Shentong view.