Both SC's and 3.2 Carrera's are great cars. I prefer the more modern and sophisticated Motronic fuel injection system of the 3.2 over the CIS injection on the SC's. Generally newer is better with respect to comfort and reliability but not necesarily lightness/nimbleness/rawness.
I would say try to find the car with the best service records, history and condition that fits your budget rather than fixate on the differences between SC's and Carreras.
I have an older '77 chassis with an '89 Carrera 3.2 engine for a great combination of lightness/quickness and reliability................but that's a whole different can of worms!
