Factory tested MPG numbers are usually not the same as what you would get in real world testing from normal drivers like you and I. As long as it's close to what they advertised, maybe off by 1-2 mpg, then I'm happy with it.
Going to wait for reviews from people who take it on road trips after breaking it in.
If Niro ever does come out with an AWD variant, the mpg numbers would go down. Some may think it's worth it, some may not. Both options should be offered everywhere and if Kia does decided to offer AWD only, I assume it'll only apply to places like Canada where it snows so much.