NEITHER is the sort of car I would own, but that isn't important to you because it's your choice, not mine. It really comes down to what you want from the car. The Calais is a comfortable car that will be quite reliable and the 3.8-litre ECOTEC V6 is reasonably fuel efficient. The Magna is sportier, handles well with plenty of get up and go. It is also reliable and stands up well. But at the end of the day, it's your money.