Not easy to point you in the "right direction". I have to say that, the coin flip sounds like a pretty good idea. This is because both models exude Panerai DNA and yet, they are pretty different from one another. If I were to choose I'd buy the 662 BUT only because I don't like the brown hue of the 687's dial. If the 687 had a tobacco dial, for instance, I would be in a spot of bother, having to choose between the two. I suggest the....coin. Once you have solved the enigma, do tell us which one you've chosen and why, please. Ciao