Interesting. I really had just assumed the iPhone was under-powered (having no idea what the device is really doing in the background). If it can go faster, that would certainly be icing. But over all, I think I'll largely be using it to sketch an idea here or there, and it is plenty fast for that. The slowdown is only noticeable for the included big reference documents. (Which are great - being able to twiddle with the features inside the definitions is now my favorite way to learn.)