I swear by the JF 15450; it’s a brilliant watch. I have a 6.75” wrist and found the JF 15400 too chunky. The JF 15450 however wears wonderfully. While the thickness is +10% from gen, the JF at 37x 10.8mm is a really well proportioned case by its own right. It’s a great balance between sporty, casual and formal