buying a 02 986 Boxster S

[Perfectlap]

well both things being exactly equal I would go for the S.
At this curb weight there is something that happens when you slap on an engine with at least 240 hp. The Honda s2000 has it and the super/turbo charged Miatas I've driven also had it. Hard to put into words but the extra torque, HP,oomph,go makes the car come "alive".
an additional 50 hp(maybe less?) over the standard Boxster doesn't seem like much on paper but it makes a far bigger impact in your gut. You don't need to head to the track to appreciate that feeling. Everytime you merge with traffic or pass a slow car you'll appreciate it.
In year's past you'd have to pay allot more for this kind of power from Porsche.
Passing it up nowadays seems inexplicable to me.