I think a large part of the appeal of the Tank Americaine is the design itself, elongated smooth lines. Diamonds are unncessary in my opinion, the shape of the watch speaks for itself.
Wow!!! Thank you for everyones input!! Plain gold it is!! But I actually ended up with an entirely different model in plain yellow gold. I got the panther mini in 18k yellow gold to wear with my plain 18k yellow gold cartier Love bracelet. Below is a pic of the watch. Thanks again for everyones responses!