There are textbooks that do things differently, and a really neat digital one coming out early next year. Sometimes bells and whistles actually provide a function and engagement, which is easy enough to disdain when kids like many of ours don't need the carrots.

Overall, I've seen some real schism factors:
- philosophy (universal design, inquiry, top down, etc.?)
- priorities
- pedagogical methodology (spiral and such)
- quality of implementation
- sensitivity to teacher talent

Like looking at Everday Math, the philosophy might sound reasonable ( http://everydaymath.uchicago.edu/about/understanding-em/em-philosophy/ ), but if it takes a nose-dive from there, then everyone condemns the philosophy. "Encourage use and sharing of multiple strategies" is not the same thing as "force everyone to guess all the multiple strategies the teacher or developer had in mind and train in the use of all of them."


Val,
Do you have some framework concepts like these that you've found useful in looking at math books?