Loved the analysis, one thing bothered me. Either I have a gross misunderstanding or the author said something incorrectly:
Fill factor is defined as the maximum percent of the fullness of an index page of data. Data can be added row by row to a page until the specified fill factor is reached. When that is reached the next row inserted must go to a new page.
I thought the whole purpose of a fill factor of less than 100% was to allow the pages to "fill up" after a reorg so that you didn't get page splits immediately? If I reorg to 80%, what do I gain when the next row is added if I can't go to 81%?
Student of SQL and Golf, Master of Neither