The Boxster base is only hauling around 1 pound more per hp...
I'd expect that to show up more in low speed acceleration comparisons. Is the 217hp base really that slow? I have an 02 S that is almost completely sorted (finally) and it's reasonably quick. Acceleration doesn't really start to fall off appreciably until we'll over 100mph. Gears 1st through 4th come and go pretty quickly and by then I'm north of 130mph.
The issue I have with my S is I have to physically look at the number to understand how quick it is. The big fat torque curve contributes to a rather flat power band...it comes to life a little bit @ 3k and then a bit more ~4k up, but it never really "wakes up" the way more "peaky" engines do; for that reason my S is faster than it feels...which kind of bums me out.