What Gill says, indeed they were faster the moment they could double trap.
We struggle in those conditions. Once we could also double trap (requires a bit more wind) we were about as fast as Kathleen/Gill. I don't know if they have improved somewhere but last year at the GC in Mumbles, with a lighter crew, we didn't have that weak spot, competitive in all wind conditions.
My take on the downwinds is that a lighter crew makes it a bit easier, just a little more time before the bow starts digging a wave when a gust hits. But technique/boat handling remains key downwind.

Geert