I'd say that NWT was the least aggressive about membership recruiting. And est/Landmark was the most. Because their goal is indeed to have everyone do their work. And they're pretty upfront about it.
Hoffstadter's I Am a Strange Loop is mostly about the role that self-referential systems arguably play in consciousness. But it also argues that parts of someones consciousness can survive after death in others.
There's a lot of that in Landmark, but from the opposite perspective. That is, there's the insight that we are fundamentally a set of "stored procedures" that we've copied from our parents, family, friends, etc. And especially those that helped us survive traumas. Such as being told that we're wrong. Or being excluded by peers. Or feeling like we're on our own.
So you get that most of the time, you're just running that stuff automatically. But if you can learn to notice that you're doing that, you have an opportunity to choose. That is, you learn to be aware of the machinery.
The bad news, though, is that there's no escaping the machinery. It's an ancient evolutionarily honed thing, and you're running on it. So all you can do is notice.
How would you compare what you personally got out of NWT vs. est/Landmark?
From NWT, I mainly got that I was chronically insecure and fearful. And that I covered it up with aggressive edginess. I still get like that sometimes, but I'm never as unconscious about it as I was pre-NWT.
It's hard to summarize what I got from est and Landmark so glibly. A key piece is that the voice in my head isn't me, but rather stuff generated from the machinery. And that listening to it just gets me more of what I often didn't like getting before. So I learned to thank myself for sharing, and then to get in touch with what really mattered to me. As they say, my principles and values. As opposed to the ideals and standards that I'd been programmed with.
I also got lots of training in how to get stuff done. Promises and requests. The importance of tracking progress and performance. The concept that being comes before, and is the key to, doing and having. The stages of projects, and especially the idea that the relationship between effort and results is hugely nonlinear.
Edit: Also, I did NWT for maybe 2-3 years. But I did Landmark actively for over 25 years.
I do recommend it. But it's crucial to keep in mind that sharing your experience of the work, and encouraging others to participate, is an integral part of it. It's true that relationships of all sorts work better with people who have done the work. So there's some self-interest in sharing.
The courses themselves generally run from Friday evening through Sunday evening. About 12 hours per day, with breaks for lunch and dinner. Back in the day, they'd run a lot later, basically until everyone got the day's distinctions. But that's mellowed since the 90s.
For example, homework assignments involve sharing with family and coworkers, and inviting them to an evening session the following Friday. At the evening session aka graduation, guests spend some time with the main group, and then go to small introduction sessions.