Shenzhen Airlines A330-300

It depends what you think you are buying. The seat matches economy for width and sits in the same two-four-two arrangement; the fare buys a longer pitch and a small, calm cabin near the front. As a legroom-and-position upgrade it is fair value; as a bigger seat it is not one.

The centre pair does; the window seats step past one neighbour. On a day flight that is a footnote, on an overnight it is the difference between slipping out quietly and negotiating with a sleeping stranger.

The two-seat window pairs of the two-four-two layout, which give a window and an aisle with nobody between you. They are the most requested economy seats on the aircraft for good reason.

The business bulkhead carries bassinet mounts, and economy has bassinet positions at its own bulkheads. All of them are limited, so ask when you book, and expect the usual bulkhead trades of no under-seat stowage and armrest tray tables.

The rows closest to the rear galleys, which take the working light and noise through the night, and the last rows generally, which queue longest to deplane. The forward half of each cabin sleeps better.