My flight changes would be few and far between. It just so happens that a day or so after I got the email, my work plans changed for a trip later in the year (which has already been booked) and I got my chance to try out the helpline. Friendly staff, but the one thing I couldn't get my head around was the fact they couldn't give me the price to change a flight until I committed to a particular flight? It meant I have left it for now as I need to sort out Car Hire and Europcar (booked via EasyJet) aren't being particularly helpful due to the website not letting me search for car hire at stansted airport for the dates I need.
I always did regret changing from Enterprise at Stansted Airport - they were always helpful and when I wasn't happy with the car they offered, they would head up to their lot and pick me out a nice Ford Focus (usually an ST-Line too!)