Fb1909, thanks for the additional info and photos!
The wrist width info helps! That seems to be the crucial measurement. One should compare their wrist width to the watch's height. 60mm width, with 45mm watch, sounds fine — that would leave 7.5mm on both sides.
Now, as to the photos, I can't tell which watch is the bigger one! Part of that is because photo #2 is slightly more of a close-up.
But the fact that I can't tell suggests the larger one would be better for more display area!
I've also noticed that some people wear their watches above the wrist “bump”, that is close to their palm, whereas others, more typically I think, wear it below it.
Spud, it looks like you're wearing that very tightly! Is that necessary to get the monitors to work, or just your preference? If I had done that when I used to wear watches, my wrist would have red lines where the band was! I'd almost be worried I was cutting off circulation…
One other observation: in many watch photos, the watches, though different sizes, look virtually the same size. That, too, says go for the bigger size. I mean, it's only $30 more… divided by, say, 3 years, is about 83 cents a month or a couple of pennies a day!
One probably gets used to the size fairly quickly, anyway, and, then, going from smaller to larger or vice-versa, probably makes the watch look HUGE or TINY!