Not sure if this is what you're looking before, but I recently wrote this in reply to someone's practice thread:
Fitter Stoke:
One way you can understand the first four ñanas - and I've never read it described this way, but it seems to be true - is that they're in a sense embedded in one another. Mind and body arises whenever the field of experience as a whole - both subject and object - become conspicuous as phenomena. Right now, do choiceless noting as fast as you can for about 30 seconds. I guarantee you'll enter Mind and Body. People naturally enter this state all the time without doing any meditation, but they tend to pop back out and re-embed with ordinary experience, because they're not trying to stay in it. Mind and body will give you a quick, intuitive, but partial feel for anatta, because consciousness and the self pull apart a bit here. There's a slight dissociated quality to it, because you're watching your mind.
If you hang out in Mind and Body for a bit, Cause and Effect naturally follows. It's just how Mind and Body shows itself if you watch it long enough: things are interacting with other things. This gives rise to that. In fact, if you're in Mind and Body for more than a few seconds, I can't see how you can fail to notice Cause and Effect. There's a sound in the other room; a quarter of a second later there's a sensation of arousal in the chest; it's immediately followed by some mental impressions. If Mind and Body is seeing that experience is nothing other than these sorts of things, then Cause and Effect is just seeing that they interact in this fashion.
Very closely related to the this-and-that of Cause and Effect is the underlying irritation or frustration in the thing. The second ñana introduced anicca; now we've got dukkha. So there's all three characteristics now, hence the name. (Anicca and anatta "support" dukkha.) You cannot perceive the source or the totality of the dukkha, obviously. But it's evident at this point. It usually manifests as physical pain that drops away quickly once you stop meditating. But it's common to perceive temperature changes, too. A lot of this stuff is probably there in experience anyway, but because you're focusing so much on it, it's really becoming conspicuous.
But there's a phase change at the 4th ñana, like when water suddenly starts to boil. Third ñana is an aspect of the second ñana which in turn is an aspect of the first. Keeping things in the same abstract terms, 4th ñana arises when one perceives the essence of the field of experience that first arose in the 1st ñana. The full name of it in the Vissudhimagga is "Deep Insight into the Arising & Passing". And that's basically the way it feels, regardless of how differently it can manifest for different people. There's an "A-ha" moment - much bigger than the "A-ha" in 1st ñana - where all of a sudden a big chunk of the Buddha's dhamma will suddenly make sense. The anatta and anicca intensify and shrug off the dukkha, and that's why people think they're enlightened here.
It's more of a conceptual framework for understanding what's happening at the 4th ñana without going into the sundry details of how one might experience it.
I've had variable experiences with the A&P. My first A&P came about a month after starting hardcore practice. Kenneth told me I was hitting 3rd ñana on some of my sits with early 4th ñana stuff. I re-read the section of MCTB that talks about the 4th ñana and zeroed in on the part where you mention the mind speeding up and no longer needing to note things. I wondered if my mind was moving faster that I had noticed, so I did a session later that day, and I realized that reality was presenting itself as these discrete chunks or frames. I realized I had biked over the hill and was now coming down the other side. I "let go", just let the attention move and sample things, and quickly realized, "My body is not solid!" I zeroed in on my hand, and it broke down into tens of little sampled bits. It was pretty awesome. My mood became manic. The next day I remember sitting on a park bench in the sun, feeling my whole body break apart and become part of the landscape. It intensified and tipped over into dissolution and the beginning of the dark night. All that week I'd get awoken in the middle of the night like someone had just hit me with jumper cables.
My next big A&P was about a week after stream-entry. I dreamed I was in a room, in some uncomfortable situation that I don't recall, and in order to resolve the problem in this dream, I had to surrender completely to my experience as it was. I could feel my consciousness begin to move "through" my body. It went in between the cells - which I could see in detail now - and passed through the other side. The cells were all vibrating and disappearing. I woke up, and there were currents of energy rushing up from the base of my spine, up over my neck and head, blasting out into space. My whole being felt suffused with love and joy. I laid in bed for the next hour, delighting in existence. (That was probably the beginning of 2nd path.)
About a month later, I had a series of A&Ps that left me unsure where I was on the path. I had one while driving which was very similar to the first one I had (very fast sampling of reality, feeling like I was in an arena rock music video). I went on a retreat about a month later, and about three days in, I left the meditation hall, sat down at a table in the cafeteria, and realized I was still very actively vipassanaizing everything without even trying. Reality was just unraveling of its own accord. Then there was energy shooting up the back and out of the head. Similar thing happened the following day during walking meditation. I actually stopped and grabbed on to a chair for support, the joy was so strong.
I actually haven't had that many A&Ps since then. I remember one over the summer where there was gentle energy shooting up my back. But that's about it.
