Drive the cars. See what they will do, yes, but also pretend like you're on your day-to-day commute. The stiffer STI suspension would suit me fine, because I like that kind of thing, but most people getting in my Prodrive-spring-equipped WRX think that it rides like a pig.
It's all wild guesses until you can get some seat time. No one here can tell you what your preferences are, or what fits your lifestyle and budget.