Apple's new iPhone 13 and 13 Pro phones -- now available to preorder -- have lots of new features that are welcome upgrades over earlier iPhone models. Battery life is longer, and there are nifty camera tricks, better displays, a slimmer notch and even some new color optionsThe iPhone 13's 6.1-inch screen is bigger than the 5.8-inch display on the iPhone X, and it should also be brighter since it can reach 800 nits of max brightness compared to the iPhone X's 625-nit screen