When you were last here, the major distinction was between Ultimas (short-term, fast-acting effects) and Major Subliminals (longer-term effects).
ZP subliminals ended up absorbing both of those dimensions. 1) They’re fast-acting in the short-term and 2) they facilitate major, deeper developmental shifts in the long-term. (Actually, a similar effect was already being noticed with Ultimas even before ZPs came along.)
And of course as you’ve noticed, they’re only 15 minutes long (and can achieve their effects with loops of even shorter exposure times than that).
With the innovation of ZP, there was a significant leap in the subs’ ability to “handshake” and interface with the mind’s internal resources and processes.
This ended up majorly redrawing the whole picture of exposure and results.
And now here we are.
There’s still quite a bit of room for interpretation.
For my part, I’ve always preferred a milestone- or benchmark-based approach to subs.
Question: If I’m driving from New York to New Jersey, when should I get out of the car? After 30 miles? 45 miles? 60 miles? Or after an hour? 2 hours? Or 3 hours?
My preferred answer: If you’re driving from New York to New Jersey, get out of the car when you’ve arrived in New Jersey.
Similarly, when you’re playing a sub, try to clarify your goals for what the sub is helping you to achieve. Then, listen to it until you’ve either a) reached that goal, or b) reached a clear plateau and may require additional resources to make more progress.
By “milestones” or “benchmarks” I mean that once you have a clear goal, then it’s easier to identify intermediate points along the way that can indicate progress.
Either way though, I personally prefer looking to life in order to gauge progress rather than looking directly to the sub; for example, exposure times. (Though I still do look at the subs a lot.)