Not worth the saving to book off-site parking, saves a few quid but the courtesy vehicle isn't allowed onto the site so you have to walk from/to the security barrier (but your friends/relations CAN enter to pick up/drop off outside the terminal!). I echo Jim's comments re the airside facilities - use the toilet landside as well if you need to. Otherwise it's pretty stress-free, and my first choice nowadays if flights available to where I want to go.
UFO