I'm interested in views about time estimation and planning.
In Socionics, it is generally assumed that Ni is the function for providing realistic estimates of time for planning purposes. However, this has some problems.
First of all, the key to doing this is to have a good grasp of reality and not assume that you'll be able to make any intuitive "leaps" to speed things up. For example, if you want to know how many days it will take you to read a very densely written book, the way to do it would be to see how far you get in one day, and then realistically consider how many days per week you'd actually read that much. Suppose the book is 1500 pages. You find that you read to page 30 without feeling too overwhelmed. So if you take a break for weekends and no holidays, it's going to take you 10 weeks.
Anybody can do this. But what types, by habit, would do it that way? I would suspect that it is the sensing types who will most likely judge time "concretely" and not rely on having some sort of "intuitive revelation" to find a "shortcut." Hence, the sensing types (perhaps both Se and Si) will be more realistic in terms of time.
The alternative view, of course, is that Ni is what does this...but in that case, Ni is no intuition at all; it would be a sensing function, because its role would then be to see things as concretely and realistically as possible. (As per the "introverted version of Ne" thread, some people think this...that Ni is a sensing function and Si an intuitive function.)
This is not to say that Ni-Ego types can't plan properly, but I think they must use some degree of dualization to do it; that, is they must think a little bit with Se to perceive how things really are, rather than their idea of how they are. It is only through using the part of ones mind that makes assumptions based on concrete, sensory experience that one will be realistic about the fact that if you can only get through 30 pages, you're not going to be able to read 300 on another day.
Even LIEs, while considered efficient, aren't always realistic in my experience. I've seen cases where LIE leaders have promised something to a client that was on a completely unrealistic timeline. They do this because they're not aware of all the sensory details that are involved in the realization. Similarly, I think Ni types in general, if Ni is really a form of intuition, would be expected to rely on their intuitive ability (e.g., "I know I can make it, because I'll come up with something"), which while it may work (because they actually do come up with a way to the meet the deadline), is not based on the more sensing, concrete, realistic approach of just assuming that no special revelation will happen and that you simply have to multiply what you can do in a unit time by the amount of time to get how long it will take.