I didn't try one of the "pay" resturants on my last trip on NCL. A lot of people say it is a must for at least one night and enjoy a quiet upscale meal with extra service. I was advised that you prebook a reservation or do it as soon as you get on the ship as the reservations are limited and the popular cusines fill up fast. Don't expect to wait until the night you decide to go as it will be too late.
I'm not a dress up kind of person so I enjoyed the open dining and the fact you are not rushed to make you meal time, especially when you have had a tiring day on shore and want to rest a little before you eat. I don't own a tux nor do I want to. Casual dress with no tie is just right for me. They do have one night when you can get formal if you so desire and that is the night they take photos as you go to dinner. I guess they call it "Elegant Night" now, usually the last night at sea.
You will enjoy open dining. I am booked on Carnival Legend and they have the same as NCL.
SS Washington 24,289 G/T 7/48 Eastbound North Atlantic
SS Ernie Pyle 10,000 G/T10/48 Westbound North Atlantic in a hurricane in October - Barf
Carnival Destiny 3/05 Southern Caribbean
Norwegian Sun 12/05 Western Caribbean
Carnival Legend 12/10 Western Caribbean