Feel Apple keeps going back between square and rounded on devices because not many other things they can change to make devices look/feel new, but hate when changes are for changes sake and worse user experience. The iPhone square edges make it less comfortable to hold and makes it feel heavier than previous years. Of course won't be holding an Apple Watch so won't make as much of a difference but think this will make it look very blocky. Time will tell.
I'm hoping for improvements in software notably for working out. Such as allowing third party workout apps to be able to use the always on display during workouts like the native workout app can. And allowing ones heart rate in the native workout app to be set to percents, such as your 80% max 90% etc, (ideally with colors) but just percent would go a long way. Also in Fitness/Apple Health you can't rename workouts like you can in 3rd party apps. So if you go to classes you can't rename workouts to be specific to that class name (while still being able to set the proper workout type). Hopefully this is something coming to the next version and ideally being able to add notes, and or tags to workouts and being able to filter those. Such as when I go on walks with the dogs I'm going to have different metrics then without, but when I look back on my progress I have no way of knowing which I had with the dog and without etc, or how my calories are different based on different instructors for classes. Having tags solves that without having to use third party apps. The problem with third party options is it doesn't sync to apple health so if they go out of business or you switch to another system some day you lose all that historic data, so would much prefer it be support first party.
And want to see some love to Siri Watch Face. In theory it's what I want, things to surface based on certain times or locations or activities, as my schedules are fairly predictable, but instead it never seems to show the third party things I want relaiblity, and instead tells me the same generic stuff always when I don't want it. Wish they allowed more control over it than simply which sources can show since Siri has proven it's not yet capable of showing what the user is expecting or wants.