I recommend True20 if you're looking for something rules and setting light.
Cons:
No backgrounds (or rules for them) for characters included in the .pdf
Though there are lots of feats, I found the feats limited (I feel this is true of d20 core too)
There is no setting; it really is bare-bones (no flavor) (also true for core d20)
Combat requires lots more DM fiat
The skills could have been expanded, especially the knowledge skills (same goes for d20)
No inherent experience point system (I recommend Clinton Nixon's rules for keys found in the Shadows of Yesterday at Indie Press Revolution)
Virtues/vices are explained, but no detail provided
Several "staple" spells are missing (esp. teleport, curse, shapechange, summoning)
No levels for monsters; no system for designing them or determining CR
Very minimal treatment of modern/future rules
Pros:
Extremely adaptable
NPCs are quick and easy to make
Combat & damage is super easy to keep track of
The magic system is simple, fun, and very elegant!!!!

Unified skill & feat charts (though I wish there was one for powers)
Green Ronin has really creative minds working for them