“The most important central characteristic in which all fully developed mystical experieriences agree, and which in the last analysis is definitive of them and serves to mark them off from other kinds of experiences, is that they involve the apprehension of an ultimate nonsenuous unity in all things, a oneness or a One to which neither the senses nor the reason can penetrate,” wrote W.T. Stace in The Teachings of The Mystics.  “ In other words, it [mystical experience] entirely transcends our sensory-intellectual consciousness,” continued Stace.
As detailed in Q&A 3 above, there are two types of mystical consciousness: the extrovertive and the introvertive.  They appear to be two species of one genus.  Mystics themselves agree that the One apprehended in the extrovertive mystical experience is the same One apprehended in the introvertive mystical experience.
In Mysticism and Philosophy, W.T. Stace provides a summary of the common characteristics of extrovertive mystical experience and introvertive mystical experiences.
Common Characteristics of Extrovertive Mystical Experiences:
The Unifying Vision – all things are one Apprehension of the One [“The Divine” or “Ultimate Reality”] as an inner subjectivity, or life, in all things Sense of objectivity or reality Blessedness, peace, [bliss], etc. Feeling of the holy, sacred, or divine Paradoxically Alleged ineffability
Common Characteristics of Introvertive Mystical Experiences:
The Unitary Consciousness – the One, the void [“The Divine” or “Ultimate Reality”]; pure consciousness Nonspatial, nontemporal Sense of objectivity or reality Blessedness, peace, [bliss], etc. Feeling of the holy, sacred, or divine Paradoxically Alleged ineffability