Apart from the indisputable advantage of wonderful onboard amenities, it is worth taking a Seville to Madrid train as it will save your time. The bus ride takes 6 hours, whereas the train ride is more than 2 times as fast. The trains are renown for running on schedule and you'll surely avoid being stuck in possible traffic jams. Plus, the prices for both transportation options are analogous, explaining the obvious price per value choice worth making.