Yup, I'd agree. Had a JFK-MSP flight cancel in May - the last flight of the day. All the evening flights from EWR/LGA/JFK were cancelled due to thunderstorms. Instead of waiting for the gate agents or CSR's at check-in to change my itinerary, I immediately called the elite line and got them to change my reservation.

It saves a lot of time and hassle.

-RM