A curious thing is the gap between Nick B. and WLVRYN. It's nearly three shots and supports a theory I have that there is a certain plateau in the 6-8 handicap range that is hard to break through. Sometimes it takes years or sometimes it never happens. In fact if you took Nick out there would be a >4 shot difference between me and WLVRYN. No other such gap exists throughout the results.
I endorse your "gap" theory 100%. I have been between a 6.5 and 8.5 index for about six years, pretty much since I began playing regularly (~70 rounds a year) again. My regular game of 9-10 guys is full of several guys in more or less the same boat -- always bouncing in the high single-digits, never lower. And when I think about it, I know lots of guys who carry a 0-2 or 7-10, but relatively few 3-6s.
So I guess the next question is: why? Why is this plateau hard to break through?