I'm lucky to have a rather sizable community of N types. In several dozen friends, I only have three close friends that are S types, an ISFP and two ISTPs. My mother is an ESFJ and my father is also an ISTP. Many of my co-workers are S types as well.
The several dozen N types that comprise my circle of friends seem rather evenly split across NT and NF. We all share a very clear sense that the rest of the world 'doesn't get us'. It wasn't until I discovered Myers Briggs that I had an explanation as to why the rest of the world couldn't see the things that we did. Until then, we were just different, high functioning gifted, etc.
S types in my opinion are...
Everywhere! It seems as if 90% of the population are S types. MBTI figures tend to agree.
Practical. They live in the 'real world'.
Surprisingly observant. They notice tangible things that N types often overlook. I have an ISTP friend who can spot four leaf clovers by walking past them, without even looking down. He does this with astonishing frequency. He'll abruptly stop moving. Back up. And then scan the ground until he finds it. I currently have one in my car that he plucked.
Empirical. If they can't interact with something via their five senses, they often assume it to be make believe and / or pointless. The ISTPs will discuss the inner workings of the mind and other abstract things, so long as there is a frame of reference with lots of assignable details. The rest of the S types I know seem to quickly jump to invalidating such subjects as if the mere possibility of them is annoying.
Suspicious. It takes my S type friends a long time to trust my intuition as implicitly as I do. They seem to have a strong need to protect their paradigm from the possibility of things they cannot percieve imperically. Even the ones who do trust my intuition don't seem to like doing so, and view it with an odd degree of suspicion that appears to be affable but waiting for it to fail so they can point it out and reclaim their paradigm.
I have a lot of trouble relating to most of the S types I meet because it seems like they don't have much capacity, or more specifically willingness to realize there is no box. I find myself being forced to stay within acceptable parameters of subject matter and conversational inflections in order to maintain a connection. For lack of a more respectful term, I feel like I have to dumb down to interact with most S types, or else they will assume that I'm stupid and check out of the conversation. Ironic, really. Granted, there are frequent exceptions to these behaviors but more often than not this has been my experience with S types. Because of this, I am usually less open to forming deeper friendships with most S types until they can prove themselves to be the exception to the norm.
In general (I wish I had a nicer way to put it) S types seem to be people who haven't figured out how to fully think, and because of this cannot grasp the fact that there could be more to thinking. It is as if they are missing a sense, and because they can't see, they refuse to accept the fact that others can. Yet, somehow S types often manage to be surprisingly sharp, unexpectedly smart, and remarkably on task despite these things.