1. Pop up windows on keywords. Want to know what venerable does/means? Tap it and you get a small pop up window explaining it
2. 360 degree pictures
3. Smooth flipping, I was really suprised at how fluidly you can move through the Ibook and find stuff you look for.
The pop-up windows are really awesome, and I can imagine it will speed up your game a lot! It will save you a lot of flipping through compared to a hard copy.
Please keep in mind I have only flicked through the demo twice, but first impressions were very good. I will buy the Ibook for my O&G and Tomb Kings most likely (when they come out).