According to the extensive data found in buildjurnal.com (see below), the boxster S calipers (F&R) will yield an identical bias to oem ZCP/CSL/Z4M brakes.
However, I have yet to find data or real world examples of this caliper upgrade being faster and/or more reliable on track compared to a properly updated oem system (ss lines, track pads, 600* fluid and cooling).
In my opinion, it’s a pure cosmetic modification.