I don't see any reason why anyone should try to convince you to get an S. If you don't feel you need it, then that's fine. Go drive the two and figure out which one makes you happy, then buy it.
Personally, I didn't buy a 986 S because I felt that they were too slow and they didn't feel as crisp as I wanted them to feel. I wanted a car that didn't make me feel like I'd want to change anything on it. The 987 is that car. The base chassis/suspension setup is nice enough (although I went with PASM) but the base engine is still a bit too slow for me. The S had the horsepower I wanted, so that's what I chose.
My desire for a fast car has absolutely nothing to do with wanting to race anyone else. I drive for myself, not to impress others.
And it's all relative--what you consider "fast" or "fun", so again, there is no reason why anyone should convince you of one over the other.