Having flown this very approach myself I can tell you it is the most spectacular, but tricky approach you're ever likely to fly. Milford Sound is surrounded by water and walls of rock. There's not a lot of room considering the huge amount of traffic this airport takes daily, and you'll wonder how you got in without knocking a wingtip off on a mountain. It's not for the ad-hoc pilot; you won't be able to go in there unless there's someone experienced with the airport sitting alongside you. But that's no reason not to one day set it up and give this approach a go. You'll be very pleased you did.