Okay so how is nothingness/no experience/no existence/the ultimate "isn't," different from being unconscious for a moment? And if there is no experience, how do you know that it happened at all? I would love to hear more from you guys if you're up for it, with thanks in advance.

Enlightenments
By Jack Kornfield
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His approach to enlightenment was not based on having any particular meditation experience, no matter how profound. As Ajahn Chah described them, meditative states are not important in themselves. Meditation is a way to quiet the mind so you can practice all day long wherever you are; see when there is grasping or aversion, clinging or suffering; and then let it go. What’s left is enlightenment, always found here and now, a release of identification with the changing conditions of the world, a resting in awareness.
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There is also what is called the “gateless gate.” One teacher describes it this way: “I would go for months of retreat training, and nothing spectacular would happen, no great experiences. Yet somehow everything changed. What most transformed me were the endless hours of mindfulness and compassion, giving a caring attention to what I was doing. I discovered how I automatically tighten and grasp, and with that realization I started to let go, to open to an appreciation of whatever was present. I found an ease. I gave up striving. I became less serious, less concerned with myself. My kindness deepened. I experienced a profound freedom, simply the fruit of being present over and over.”

On Enlightenment – An Interview with Shinzen Young
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When it happens suddenly and dramatically you’re in seventh heaven. It’s like after the first experience of love, you’ll never be the same. However, for most people who’ve studied with me it doesn’t happen that way. What does happen is that the person gradually works through the things that get in the way of enlightenment, but so gradually that they might not notice. What typically happens is that over a period of years, and indeed decades, within that person the craving, aversion, and unconsciousness—the mula kleshas (the fundamental “impurities”), get worked through. But because all this is happening gradually they’re acclimatizing as it’s occurring and they may not realize how far they’ve come. That’s why I like telling the story about the samurai.

This samurai went to the Zen temple on the mountain and lived there for many years. He didn’t seem to be getting anything out of the practice. So he said to the Master, “I think I need to leave. Nothing’s happening as a result of this practice.” So the master said, “Okay. Go.” As he was coming down the hill one of his former comrades, a fellow samurai, saw him in the tattered robes of a Buddhist monk, which is equivalent to a glorified beggar from a samurai’s point of view, and he said, “How could you be so undignified to join the counter-culture of Buddhist beggars?” and he spit on him. Now in the old days the samurais were extremely proud. Any insult to their personal dignity meant a fight to the death. So the monk who had formerly been a samurai just walked on and after he’d walked a certain distance, it occurred to him that not only did he not need to kill this guy, he wasn’t even angry.

As the story goes he turned around and bowed toward the mountain three times where he had practiced. He bowed in his recognition of all that he had worked through. He recognized he no longer needed to kill someone that had offended his dignity. He noticed how fundamentally he had changed as a human being.

Of course, it’s not just samurai in sixteenth century Japan. The same things apply to twenty-first century North Americans. Maybe they’ve been practicing for ten, twenty, or thirty years and it doesn’t seem that much has changed. And then something big happens like a major bereavement, a major illness like cancer, a serious injury, or their life is somehow threatened. Then they notice how everyone around them is freaking out and how much less they’re freaking out.

I’ll give you an example that happened just a few weeks ago. Someone who has been coming to retreats for quite a while went to have a biopsy to determine whether they had a serious cancer or not. While waiting for the results, this person noticed they weren’t worried. Anyway, it turned out that the biopsy was negative. So all the unnecessary suffering that would’ve happened but didn’t, that was the effect of that person’s years of practice. It’s my impression that many more people have that gradual unfolding than have the sudden,

I like to analyze subjective experience into three sensory elements: feel (emotional-type body sensations), image (visual-thinking), and talk (auditory-thinking). Those sensory elements continue to arise for an enlightened person. However, the frequency, duration and intensity of identifying with feel-image-talk diminishes as the months and years go on as you go through deeper levels of enlightenment. There are exceptions, but typically it takes months, years, indeed decades to learn how not to get caught in feel-image-talk when it arises.

Enlightened people have three kinds of no-self experiences. In the first subjective elements of self simply don’t arise. Subjective space vanishes. As the process of enlightenment deepens you experience longer and longer durations during which little or no subjective activity needs to arise. In the second emotion in the body and visual thinking and verbal thinking all arise, perhaps even intensely, but because there is so much clarity and equanimity present you’re not caught in them. In the third the subjective elements arise and you do get caught in them but some part of you still knows this experience is a wave called body-mind, not a particle called self.

Papa Che Dusko
In my "after" experience it kind of felt like something ripped me out this reality and did to me what ever they fucking wanted to do and then shoved me back into the same place. I was like "what WAS that?!!!" So in retrospect I felt afterwards a bit like I was "violated". 
Nothing special. No bliss or after bliss or rapture. Just plain life going on.

Papa Che Dusko
Also to add but could be off here; cessation is abrupt in its "after" feel. Bleeps, passed out and being in a trance or a dream, sleep, anesthetiser, all have a bit of "gliding into the conscious or mindful. There is transition "space" to it which lacks in cessation.