My sweets spot in terms of case size would 42mm. Legibility is important to me but I also like a watch with strong presence on the wrist. For these reasons, when I deviate from 42mm, I tend to go bigger rather then smaller. I have grown quite found of the Panerai 47mm case series which are my favorite “big” watch - they actually don’t wear that big. I love the weight they bring on the wrist. Now for a dressier watch I am ok going down to 40mm or 39mm like my Up/Down but this is as low as I would go - I seem to have a mental blockage for anything smaller then 39mm...