"Which Witch is Which?"
That's a children's book the title reminded me of.
It sounds like both are accurate, and remarkably the same. You evening weight is going to be different than your morning weight and you can't compare the two. If your weight was lower in the evening, well then wahoo! Expect a drop from your morning weight!
I say just pick one. My preferred one would be the one I could get on quickly and get naked.
That's the not the Wii at my house. It takes too long and I can't stand in my family room naked with two boys in my house.