kinect is more acurate and more responsive but for the kids and family fun the wii is the better option simply because there are more games for the wii that are for kids.Kinict is better though because like i already said it is more responsive,acurate and you dont need to hold a controler for example when boxing it just follows your hands.
heres a youtube vid of some guys doing the sports package.No controlers just run on the spot like mad lol
got the kinect for the lads for xmas and so far i have resisted temptation to test it out lol