Walt Mossberg recensisce iPhone 4.
I've been testing the iPhone 4 for more than a week. In both hardware and software, it is a major leap over its already-excellent predecessor, the iPhone 3GS.It has some downsides and limitations-most important, the overwhelmed AT&T network in the U.S., which, in my tests, the new phone handled sometimes better and, unfortunately, sometimes worse than its predecessor. I'll get into that below. But, overall, Apple has delivered a big, well-designed update that, in my view, keeps it in the lead in the smartphone wars.