I went 38 after thinking I just had to get bigger one, everyone said bigger is better. Well, extremely happy I did not do that, 38 feels better, looks more like a watch and working just perfect.
You're not getting extra real estate just larger text/icons, if your eyes are good, and you like the 38, go 38.
It's all about how "you" will use it, so far I hardly ever have my arm up staring at it, mostly quick looks and using siri. You don't need treat the decision like a TV screen or monitor.
Don't let others decide for you, we are just giving our opinions, think about how you are going to use it and ask yourself why you need or want a larger watch or smaller watch. Eyesight, fashion, fit, feel, it's not just bigger is better in this case.