That's a fine, eerie description. I think illusion remains, for the mystic, but it shifts to mundane experience, to maya, the illusion of a plurality of material essences. Egoistic perception becomes the illusion or the daydream, and recognition of reality is reserved for the few who withdraw from the mass hallucination.

Still, there's the pesky conflict between rationalists and empiricists in the history of philosophy. The problem with mysticism is that it's more empiricist than rationalist, so it's vulnerable to skepticism about all first-hand encounters. No matter how real something seems firsthand, we might be mistaken in interpreting its meaning. And the encounter itself is the product of some channel or form of conveyance which might skew the data, as it were.