Gosh, I haven't checked to see if there's a difference. I've been avoiding Wii fit since I got my bathroom scale because it says I'm heavier and I was waiting until I lost a pound or two so the Wii wouldn't chart me as gaining and ask me what I've been doing wrong >.>
mine are fairly similar, I do a weigh in with the wii when the bathroom scale says I've lost and seems to work for me. Use what is convenient, I am with not going down to the family room and firing up the wii etc. if I am not about to work out. Its the general trend that is more important.
also, my family room has a carpet, which is not thick but may have an effect on accuracy for the fit. Ditto some bathroom scales if the floor isn't quite level.
both scales showed a loss this morning, Wii Fit weighs my less, about a 2lb difference but my bathroom scale is very old, like 7yrs or so if not more, so I think I will go with the wii fit. I always send my son out of the room and weigh myself naked, before I eat breakfast...lol.
So, today I decided to test the scales. I have 2 3lb weights I put them on my bathroom school, it read 6.5 (my scale on does .0 and .5)I made up a Mii and weighed the weights, it read 6.2. Yet for me, its a about 2.5 weight difference. weird huh??