I'm too locked in to the Apple ecosystem to switch, but I really wish they made a round watch. This one looks so good compared to whatever Apple puts out every year. A round watch face just makes so much aesthetic sense.
If you're fitness first, tiny screen strapped to your wrist second, they're excellent devices.
You would need to refactor the entire UI interaction model to properly take advantage of a circular face.
You can fit less information on it, even with the same number of pixels. There is nothing you can do on a round LCD that you can't do on a square. If you find it aesthetically pleasing, great. I like round as well. But for people who like round, and use round to display a clock face, try a mechanical watch. They are awesome. ]