Since the biggest change in the 5T is the display, let's get right into it. With a new 18:9 aspect ratio and a slightly weird resolution of 1080 x 2160, the 5T is at once alien and familiar. Its pixel density of 401 ppi is ample to ensure clean, sharp images, and on first look you might not even be able to tell it's an OLED display, owing to OnePlus' hard work on tuning color rendering. There's a broad set of color calibration options, including sRGB, so most people's tastes should be sated by this screen. The unfamiliar thing about it is the elongated shape, which has only just started finding popularity this year with the Samsung Galaxy S8, LG G6, Google Pixel 2 XL, iPhone X, and a few others moving to it.
I spent some time with the OnePlus 5T ahead of today's announcement, and I can say that its ergonomics haven't suffered one iota from the major change in display. Yes, the fingerprint sensor is now on the rear rather than the front, but it's still every bit as fast as it's always been, and OnePlus has added a new face-unlocking feature for those moments when you want to access the phone while it's sitting on a surface. The face unlock simply uses the front-facing camera, it's nowhere near as complicated as Apple's Face ID, but it still works with surprising accuracy and speed. If I value convenience higher than security, I'd use and recommend it without hesitation.