Hi all,
sorry for getting this thread up, but I just got my Trail Loop im M/L size. I have a wrist size (17.5 cm) where both sizes could have fitted (according to apple) but I decided to go with M/L. Yes the small loop part does not align perfectly in the middle, but there is about 3-4 cm to go until it reaches the case.
And you should also bear in mind the following when choosing the size, especially if you are in between sizes.
The size of your wrist could change (though of course not dramatically) during year, because of temperature.
In summer, when the temperature rises, the blood vessels on the surface of the body dilate, which helps to remove excess heat from the inside of the body. This also leads to fluid leakage into the surrounding tissue, as the vessels become more permeable. Thus, your wrist size increases (slightly)
In winter, when it is cold, it is the opposite.
Best regards.