I just finally finished reading my copy of Numenera.  I could - and would like to - talk about the setting and the mechanics, but I'd like to have a chance to play a session or two first.  So why do I even bring it up?  Easy.  I want to talk about something even more nitpicky:  the layout.

The Numenera core book has one of the best layout choices I've ever seen in a gaming book (or, indeed, any reference book):  annotated margins.  Whenever an in-game concept is referenced anywhere in the text, there is a margin note pointing to the relevant section or sections of the book.  Having read through my share of poorly-organized corebooks in the past, it was amazing to me how much of a difference this layout choice made.  Granted, it must have required a considerable amount of time and effort to cross-reference all of those sections, but doing so made understanding the book so much easier.

The margin annotations weren't all cross-references; some were flavor notes, and others were additional relevant statistics (e.g., for a referenced NPC).  Those were great as well, but the cross-references really sold me on the value of the book's layout.  I'd love to see more gaming reference books structured this way.