Have seen both opinions.
Pigs definately benefit from being hung for a couple of days, helps the meat set-up, and makes easier to cut.
They certainly don't get any worse for being hung longer, so don't panic if your butcher can't cut it for a week or two (as long as it's in his chill room).
Some people like Sally do swear that it improves the flavour.
It would be an interesting experiment to butcher one side after 2 days and then freeze it, hang the other side for two weeks then butcher and freeze it (so both are equal). Then unfreeze and blind taste. Maybe one day when she lets me retire I may try it !!