The Steadfast Order of the Shapers of Earthly Splendor provides an excellent and inspiring writeup of a secret society based strongly on Freemasonry. Despite the series title, this faction is not closely tied to the planes, and could easily be dropped into any setting that needs a Mason-like group as antagonists, allies, or patrons.
Physically (if one can use that term for a PDF), the file is black and white, with no art. It is 17 pages overall, but uses one page for the d20 license, one page for a preview/ad for Planar Factions Collected, and half a page for a really huge title. The clean, no-frills layout is very simple and readable on the screen, and at this length it doesn't need to be broken up much to rest the eyes. The only decoration is the header font, which is clearly intended to call Planescape to mind.
The PDF details the history, beliefs, and customs of the order, the benefits of belonging, and a set of feats that may be taken by members that allow them to perform certain magical functions such as crafting simple magical items without being a spellcaster, allowing those within a building to draw upon magica power infused in it like a wand or staff, or geomantically arranging buildings to make them easier to use your divination spells on.
The biggest flaw is that no NPCs are described. I can understand not wanting to tie characters down to stats as each DM's campaign is going to be different, but sample members of the order could only be a good thing. Another possible addition for expansion would be connections tying this faction to the others in the series, even peripherally.
Overall, this is an excellent PDF, one that both encourages me to buy the full book and look forward to more in the series.