Norwegian is offering amazing fares to Gatwick, direct flights in many cases. The cheapest fares allow for 1 carry-on and handbag- with a combination weight of 10kgs (read the conditions for your fare twice). At Gatwick, at check-in, they check your carry-on and handbag weights before they issue the ticket. They tag your carry-ons. At the gate and before boarding, that is after you do security, they have a scale and they do a second check of the weight of your items. In all, if you exceed the limits of weight, you must pay either at the first check-in or at boarding. I can tell you that at arrival at my final destination, about 75% of the passengers were waiting for luggage. The carrousel had, as expected, tons of carry-ons. In my case, we were 2 traveling and we got charged for one bag. At the first counter, they did some weight redistribution math and charged us 70 pounds for one bag, 20% of the roundtrip fare.
The service was very good although I had a 2-hr delay at departure. If you pay for meals, they go seat-by-seat delivering your order. If you did not pay for meals, you can buy everything on-board- including water. There is no free water service in long flights; my flight was about 9 hours. All drinks are between $5 and $10 on board. My flight had free Wi-Fi, slow on the first flight. Hard to connect on the return one. Bring your headphones, or you can buy a set too. Have a great flight.