The game has always been somewhere between role-playing and wargaming, and with 3E it definitely shifted more towards wargaming with an emphasis on crunchy rules.  
I have preferred that shift toward rules and away from substance because I have mostly run home-brewed campaigns, and I'd rather pay for good rule systems than pay for interesting reading.  
Lately however, I have less time to prepare games (and sometimes no time to play 

 ) so I can see the need for less crunch and more substance.  
There is certainly a sweet spot for me when it comes to rules and ideas in gaming books.  I think the best game books have great ideas that are backed up by solid game rules.   
For example:
- A dissertation on how elves are expert hunters might be interesting.  
- An elven prestige class by itself might be useful.  
- An elven prestige class backed up by a couple of paragraphs describing how they are expert hunters is ok.  
- A section on elves that explains how they are such expert hunters in this part of the world backed up by an interesting elven hunter prestige class, a sample NPC, and a couple of new feats and spells is great.