Honestly I really liked the J12, but I found the design often copied by other watch makers and I always thought the ceramic links looked 'plastic'. So I always liked the look of it, but not really love it. Plus if you add diamonds to it, not only does it look odd with the diamonds/plastic look, but it would also look gaudy.
On the other hand, the Dior VIII sang to me as soon as I saw it (thanks to
@averagejoe I am looking at you mister I constantly drool over your VIII whenever you post pics of it). I love the detail of the VIII in comparison to the J12 and it still looks sophisticated if you choose to have diamonds with it. Plus the links of the VIII and the bezel is unique to any other watch I have ever seen.
But alas, I still haven't purchased one because I am still on the Rolex/Cartier/Patek Phillipe/ Jaeger Le Coutre/ Audemars Piguet, etc., etc. bandwagon (well my dad is and I borrow his watches all the time

and well yeah I love his watches) so I never really saw the need to buy a watch for myself, and I don't want to be judged by a bone fide watch snob aka my dad.
The only watch that I did purchase for myself is my trusty Citizen watch I have worn consistently for the past 6 years on a daily basis.
This is just my opinion but yeah it seems like everyone else here loves it though

Buy whatever sings to you as its your money and not mine!