Very interesting post, and without taking position let me say you have two superb Aquanaut references here (I'm assuming, by the 42mm size, that the green is the 5168G rather than the 5167A LE). That 5968 on the orange strap is a real gem! ;-) Cheers.
But I personally find the Aquanuats to be more wearable and visually appealing than a Nautilus. Having owned both, I just prefer the size of the Aquanuat and the 42mm size. The Nautilus and the 40 mm size is for my wrist and preference is just too small. ...