The 3.2 is worth what you pay for it and the 2.5 is worth what you pay for it... both cars are exceptional, you will not be disappointed with a 2.5.... You can resale an S much easier though so keep that in mind. If you are particularly power hungry though i would suggest a 2.5 for the time being and taking the money that would have went to a S and put that towards a Carrera engine swap.
Hope you find the right car.