Pitch is far better, if seats feels better it is a personal preference. AVOD is said to be super. Meals are the same as you buy in economy. In Premium the meals and one drink (soft, beer, wine pr. meal) are included. Besides that it is pay for what you want, order and pay via AVOD-screen

From Norway the prices in Norwegian Premium (non-stop/one-stop) is sometimes at the same level as BA WT+ (one stop). During good BA-sales Ex EU it has been the same or above CW. (OSL-LAX is now the same in BA CW-sale as Norwegian Premium Flex)

(Have not tried Norwegian Premium myself, but have several sources)