I don't like the curved back. When I lay my table on the phone I don't want it to sit there and rock back and forth. I don't want it to be unstable. I want it to lay flat. The two dimples on the flip-out kick stand are there to serve as feet and make the back of the phone quasi-flat but they are too close together, and the other "leg" is the camera's bezel, meaning it will get scratched up and the finish or plating will chip, scratch, tear and wear away as time goes on.
I don't like the position of the kickstand. Placing it on one end puts the pivot point for the phone to tip over near the center of the phone, making it more likely to tip over at the opposite end. The strongest shape is a triangle, and the most stable positions of a 3 legged stool is in equal distances from each other in a true triangle formation. In this situation, the best location for the leg is center. Even though it isn't a perfect triangle, it will be the closest thing to a perfect triangle.
I'm not a fan of curved glass since it acts to bend light. The concave curve of that screen will create a reflection of your face that will be extremely narrow and tall (full height of the glass), and concentrated right down the middle, so that what would normally be a rather muted reflection of you and what is behind you in a rather dull intensity that covers the entire screen will instead be bright and hard to avoid right down the middle. With a flat screen a slight turn removes yourself from the "mirror" image you see on the screen. With a curved screen, turning it either left or right will only cause the image of the reflection to remain in the center of view and move across the screen in the direction of the turn. If you tilt it up or down you'll get the same narrow and long reflection of whatever is directly above or below your face - sky or your shirt.
I do like the additional LED notification lights. The only problem with notification lights is if they aren't devoted to one thing or another, remembering what they represent becomes difficult. Take difficult times 6, and that's what you are looking at now.
There's more but that's the big ones for me.