This may not be what you want to hear but the run of the mill Mazda MX-5 has always had a better suspension design than the Boxster. The MX-5 has dual front wishbones whereas the Boxster has the cheaper to manufacture and poor camber curved front MacPherson struts. Given the same power and rubber, a MX-5 can hang with or possibly beat a 986 in the corners (depending on driver, tires, wear/age of the components, etc).
This is a good description of the two suspension designs and their benefits/drawbacks:
Comparison between MacPherson & Double Wishbone Suspension System
Threaded Mode
