I was wondering how the face tracking 3D metering would work exactly, having never used any face tracking before. But the way you describe it, it seems like it would be great for weddings. For the formal group shots (not my favorite) I use non TTL strobes with umbrellas with wireless receivers, and not my sb-800's/900's. So I suppose that I would have to go to the to the SB's to get any benefit from the face detection exposure. Today, I use a light meter and shoot these on manual. But this takes slightly longer to set up.