Just for arguments sake....

The quote above references 2 crew weights, which (to me) may mean two dfferent crew members. Could the performance difference you experience be related to having different crew onboard? Certainly crew work would reflect on your ability to get around the course/manuever/etc.

Just asking, as your assertation seems to be fairly general and COULD be misleading to the exact cause of the decreased performance.

No disrespect to the crews involved, of course.

EDIT: BTW I try to keep my boat down to minimum. I think it is challenging and it gives a mental edge. I just wanted to point out that there MAY be an issue with the general logic of the above-mentioned quote. End Lawyer-speak.