The impression that I get is that most people would be fine with the 42mm. Perhaps if you have very small wrists it might make a difference. These are my findings with size.
1. I may be a guy but I don't like ultra large watches - Rolex Submariner would be about the largest I would want to wear and that is tiny compared with a lot of both high end and 'fashion' watches that I see worn day to day.
2. There is not a huge amount of difference between 38 and 42mm. Just because the 42mm is the 'large' size does not mean that it is large compared with many watches.
3. Because it has a touch interface, it makes sense to use the largest screen that is comfortable.
4. Don't worry about the corners of the square screen. The bits that you feel on the wrist are the edges, so compare it with a circular watch that has the same width and height as the apple watch.
My guess is that the only people that would not like the 42mm size is those people, mostly women, who have only worn watches with tiny faces.
1. I may be a guy but I don't like ultra large watches - Rolex Submariner would be about the largest I would want to wear and that is tiny compared with a lot of both high end and 'fashion' watches that I see worn day to day.
2. There is not a huge amount of difference between 38 and 42mm. Just because the 42mm is the 'large' size does not mean that it is large compared with many watches.
3. Because it has a touch interface, it makes sense to use the largest screen that is comfortable.
4. Don't worry about the corners of the square screen. The bits that you feel on the wrist are the edges, so compare it with a circular watch that has the same width and height as the apple watch.
My guess is that the only people that would not like the 42mm size is those people, mostly women, who have only worn watches with tiny faces.