A good friend of mine has one,which she has owned from new.
They are very good cars,but beware of the costs of running one. Some of the service bills she has had to pay were truly huge. As I said,she has owned it from new, and she only does a tiny mileage and she has never had any big problems with it,just routine stuff.
I once owned a 1989 280GEL and loved it, 15mpg everywhere, motorways, side roads, in town, no difference. The diesels fare a little better, but still in the lowish 20's I think. I have not looked at the newer ones as many of them are left hookers. Bought my G in 1999 ish for about £15k, good versions are stll fetching around the £7-8k mark. I would like a 300GDL auto, but almost as rare as rocking horse droppings.