I have not picked up the actual book yet, but I did buy the PDF, which I have printed out and put in a three-ring binder. I have to admit, it is everything I always wanted from D&D 3.5 and more.
Some of the bits I really like:
-The flexibility; the classes and races are generic enough and the feats and skills are numerous and many-use-ed enough that customization is easy
-Gear that makes sense; the weapons, armor, items etc. make sense (as does the silver piece as the main currency unit), unlike in D&D
-The NPC/monster creation mechanics are super easy to use and provide options to build whatever you can think of
-The reputation/magic item rules are a new and interesting mechanic for me; the race to gather as many magic items for your character as you can to stay competitive is replaced by a few magic items that actually mean something storywise and by other rewards (holdings, contacts etc.)
-The magic system is similar (in all the good ways) to 3.x D&D, but different and improved in many ways; spells seem to be balanced and the new mechanic for determining spell save DCs make lower level spells much better later on
The game is very generic and open to creating whatever you need. I typically GM, so the sandbox-ness of the game suits my style well.