Just tried Norwegian transatlantic for first time. A mini-review.
As SLF with no weekend stay, BA and VS fares were astronomical. DY was a nobrainer at a fraction of the cost, with lounge access.
Via Twitter, they advised me that they did not offer Fastrack security access in PE, but this was not the case and it was indeed included. After me paying £4.99 to Gatwick Airport separately for the privilege.
At check-in, they told my friend that he might be refused access to USA because his passport was invalid. This was absolute nonsense but made for a fretful flight. I was fairly relaxed because I think DY would have been fined if they got it wrong, but still... its not nice to board a flight with doubts in your mind, knowing how awful US immigration at BOS can be.
The seat was comfortable with excellent legroom (proviso at the bottom)
Food was an issue in PE - the included portions were tiny and all our party were ravenous by the time we landed in Boston.
The sandwiches were wet, and basically unedible.
Norwegian were also extremely strict about standing near the galley (and by default, loos) claiming US law forbade people standing there. Funny, no one has told VS or BA that!
And don't pick a window seat unless you really know the person next to you - when seat in front is reclined it is extremely difficult go get out for a loo break...
Would I use them again? Probably. And pick and aisle seat.
But I'd really try to rearrange my dates to include a Saturday night stay and use BA or VS.