I've given up on Gatwick as I can't remember the last time when I've used it during the last ten years... having to negotiate the car park laughingly called the M25 makes onward travel a lottery... travelling to Alderney from the UK you would be quicker routing direct through Southampton that would be a lot more convenient.
You should give Gatwick one more chance one of these days. Under new ownership it has changed considerably for the better. After the lane-widening, the M25 is no longer as bad as it was ten years ago; I've managed many a connecting flight by using the National Express services which are very good and have never suffered a delay. You say it would be quicker to go from SOU but often it is more expensive (which, including train fares, adds up to £80 more on a two person return booking), and also takes marginally longer when I only live ten miles from LGW (out of three journeys this summer, I am only using SOU once). Back to thread however...