Having tried both routes (albeit, CX from JFK) in Y, they're very different products. The biggest change will be the seat goes from a Recario slider to a foamy recliner. The recline could be better, but it does just barely meet the margin for ok on such an ultra-long haul. The staff service is very good for both routes. CO's AVOD is very very good (albeit, rather different from CX's) and is a big factor in making the flight more enjoyeable. Naturally, food is inferior. Hope that helps.