The only issue with more variety per monster means something else has to give. Either less monsters or less fluff per monster. Quite frankly, I'd rather just be given templates at the back of the book that can modify monsters, rather than two or three examples per monster entry and greatly reduced monster count or less fluff.
I have no interest in going back to applying templates and class levels. I loved the 4E treatment, but I do agree, it creates a space issue for the number of monsters. They could just release, you know, 2-3 books on monsters all at the same time....