#1, go with your heart, not your head.
#2, if you wish to speak investment and return-on-investment (if you actually plan to sell the watch one day), popularity often drives investment value (though I think marketing does so more than any other factor).
That being said, the Duoface was "Watch of the Year" in 1994, and has remained JLC's best selling Reverso for 20+ years now. It has NO competition in the market place (as far as design goes), and is a tribute to JLC's GENIUS: doing what's difficult on the inside, so that it's easy for the user on the outside.
Again, go with your heart, not your head.
-Dean