Yep, reflector before flash every time and I'd rather use a video light before flash too
One of the reasons that I still second at weddings and my friends also second for me.
Having someone who will look after the kit, knows how to use a reflector and will scout the locations with you and generally watch your back is invaluable
Knowing how to use a reflector is important though. It seems like a very simple thing just to bounce light around but it has to be coming from the right direction and the most common mistake I see is height. Get the thing as high as you can, the sun does not come from waist height! (unless you are using it low down to bounce light up it should go as high as you can)