I think the 38 looks better, as an elegant watch. The larger one can pass as a sports watch. It comes down to your style really. This more than anything comes down to your style of dress and wardrobe. Personally I dress up for work and generally wear fitted clothing. I don't wear watches at the moment but if I did it wouldn't be huge sports watch.
It really is very nice. I'm glad I preordered it yesterday as a secondary band. It's not one I will wear everyday but will make a nice change from my regular black sport band.