You can go to the Entertainment book website and put in the zip code for Orlando and see what all discounts are in the book. I couldn't find any for Universal or IOA. I actually never saw any for T-Rex or Rainforest even though I have seen someone on here say they have coupons for DTD restaurants in the book.
I bought the 2011 book that expires November 1st for $5 thinking there would be some good DTD coupons in there but there's nothing. Total waste of money. But I didn't know at the time you could go look at all the discounts listed alphabetically, on the website. If I had then I wouldn't have bought the book.
The discount they offered for Cirque tickets at $80 per ticket was way higher than the $53 I paid for them by joining Club Cirque.