The only problem I had with Norwegian on the one long-haul we did (Bergen to JFK) with them was not Norwegian's problem. It was the airport.
We were in a gate that had (I counted) about 40 seats - and our flight was a 787 with several times that number of people having to stand around.
You could see construction going on in many places so I'm hoping that, by now, that problem has been alleviated.