Before checking, would you guess that the top 15 have higher, or lower, % positive scores than most users?

Hm.

I would expect the typical LW user with a karma score above, say, 1000, to have a %positive of approximately 90%.

Among users with karma < 1000 I find myself wanting to distinguish among "new active users", "lurkers", and "long-time active users." I'm not exactly sure how to define these groups operationally. Long-time active users with K<1000 I expect to have %positive of less than 75%. The others I'm less sure about.

The more I think about this, though, the more it gets cluttered in my head with the basic problem of karma correlating with number of comments posted, and therefore with post frequency and tenure. The statistic I'd actually like to see for users is average comment score and average post score.

Anyway, to answer your question... if the average among the top 15 is 90.6%, it seems I expect the top 15 users to have approximately equal %positive scores to most users above 1000.