I chose the 5165. I don't have a small wrist or forearms, and I think the watch looks just great. The 5165 is an everyday wearer for me, and I prefer this size for that purpose. I wore a Rolex GMTII for a while, and even though it's only 40mm, I tend to "notice" I'm wearing it. When I am relaxing, the bigger the better. But when I'm working, I like it to fit a little smaller, if that make any sense. I guess it boils down to whether you are a 38mm or a 40mm watch guy. Most folks prefer 40mm watches nowadays, but I for one am glad they made this in 38mm, because I sure do enjoy it. Good luck with your decision. It is a fine watch!