modern electric fan ovens are quick to heat, and give a regular temperature throughout the oven so you can do, e.g. several trays of cakes
Gas ovens are hotter at the top than the bottom, so handy for e.g. roast potatoes on the top shelf, joint in the middle, pudding on the bottom. They also seem to put a better skin on a rice pudding (I like skin) and I think there is less cooking smell, as the smell, smoke and fat vapour seem to burn up in the flame.