I know others will have FAR more experience than I do here, since i've only done it once. I for some reason, was op-uped on an half full flight to Shanghai a few years ago on Shanghai air. The seats are indeed far bigger and there was priority boarding. Don't remember the meal (I was either asleep or it wasn't memorable).

One still gets a meal or some sort of food in short haul domestic Y in China so I'm sure the offering in F will be better. Service was typical (ie. indifferent, but not mean).