I bought a non-S without ever driving the S. Why? Mostly due to "value". I had the cash to buy an S, I just chose not to.
The non-S is good enough for what I'm going to do with it (weekend drives on the coast, top-down motoring with the wife, spending Saturday afternoons in the garage fiddling with it, etc). If I was still auto-crossing or running track days I would have gone for a S without hesitating because I would kick myself for not having that extra power, better handling, etc. Since I have no plans for that, the added expense wasn't worth it for me, and I focused on finding the exact car I wanted with the exact options I wanted (and didn't want) and never looked back.
As a total aside, I drove a Mitsubishi Evo IX the day before I bought my boxster. I cross-shop some odd car combos.
