Kathleen and I weight 300lbs/135kg, on the last Dutch nationals we did really bad in the lighter stuff against Geert&Raymond weighing about 150kg/330lbs (I hope I'm guessing good, luckily they are 2 men so wouldn't mind too much if I rated them too heavy :-) ).
On the other hand, once we could double trap upwind we were faster. Mostly because our boattrim trim in those conditions is getting really good.
So here clearly the weight was not a key factor.

On the downwind I think weight is even less important, you just have to drive the boat differently. Lighter crews will go deep and a little slower, heavier crews can really push the boat to the end and go for speed.

Let some different configurations take gpsloggers with them on the GC.

Gill