Before I got my iPad, I thought 7" would be the sweet spot for tablets. However, I have to say that Apple got it exactly right with the screen size: the iPad gives you enough size without being over-large. 7" screens don't give you any real benefit as they're still not pocket-able so all you are doing is losing screen real-estate for no real benefit (or else you are simply reducing the size of the screen and making it less clear)