I have to say that, overall, NCL is my favorite cruise line.
The main reason is: Freestyle cruising. This feature is no longer "unique" to NCL but I like the variety of dining times and venues, relaxed, but not abolished, dress codes, decent cabins and great and diverse entertainment.
The overall cruise fares are on par with other mass market lines but you do need to budget $100 - $150 additional per person to truly experience the alternative dining.
It's interesting that my favorite cruise line has my least favorite ship. Epic left a bad taste in my mouth. The entertainment was great, the service wonderful, food EXCELLENT but the ship's look, design and cabins, left such a negative impression on me that I have no desire to sail on Epic again. I know it's a bit weird but it's just how I feel.
I REALLY looking forward to sailing on Breakaway. I think they took what's right with Epic and kept it and took away what was wrong with Epic and dumped it.