Well, simple answer is; of course it's better. Unless you're only looking at it from a budget perspective, it is a slight overall improvement. Namely, it's at a smaller manufacturing process, 32nm for Sandy, 22nm for Ivy which gives it an undeniable processing power/efficiency advantage. Plus, Ivy Bridge has some added features and all that blah-blah.
But as the the above member says, it's not really worth a new cpu/mobo.