Patek Philippe Nautilus question

[braungeo123]

Why does the Jumbo Nautilus in the blue dial have a plain steel back while the rest of them have skeleton backs?

Also, Is there any difference between the swiss eta and the less expensive version? Is it better quality or not?


I am looking at this one from watcheden. Thanks

http://www.watcheden.com/patek-philippe ... 6-p-1.html

 

[braungeo123]

Anything? Do people like this or the royal oak offshore with the black dial better?