I have the good fortune to have the opportunity to purchase from my local AD either the 5165 (38mm) or the 5167 (40mm). My wrist size is 7.25 inches. The 5165 appears slightly small on my wrist, while the 5167 appears slightly large (which I don't quite understand, because my Nautilus 5711, which is also 40mm, appears perfect in size). Any advice from you sage contributors to this site? Many thanks.