You seem like yo uhave powerful cars for your family from the 240 to S70 model. Even the other has 16valve on a 2.0 engine. S40 however is like the entrance model for the Volvos- the bare basics model. I think that is being too minimalist. Unless this of course will be your wife's car and you have a vendetta against her- or she likes driving at 55mph and no more. I still think you could consider ammenities besides performance. I say just upgrade or stay at the S-70 level.