I played with this at the NY toy fair in February. The words game is really cool, you find yourself digging through letters as quickly as possible while trying to form the word but you also have to watch to make sure you are actually on the right track before you shove too many out there, and watch the other player too. The game is scored by giving you points for getting the word but you also lose points for every letter you shove in that isn't right. If you want you can just shove the whole stack in front, you'll instantly solve the puzzle but with an enormous negative score.
Something about that particular game is an experience I haven't had with either physical or digital games before, whereas most physical/digital hybrids I've seem could just as easily be done purely in one or both realms.
The tangram seemed like a bit of a dud for that reason, for example. It is nice to be able to get hints while playing physical tangrams (it can show you just the outline but tell you if you have a piece in the right spot), but that isn't really that much of an improvement over just having the pieces or just an iPad game.
The physics game where you draw on the pad is a strange demo to me. You can just do it as a drawing game without the paper, which is a bit less social, but again, this isn't much of an improvement. What is really cool, though, is the interactive outline of your hand or any object you put in front of it. But it doesn't really encourage that in any way, it just feels like a tech demo.
All that said, this product does excite me just because the word game gave me a feeling I haven't gotten in either a purely physical or purely digital space.