Kia Sportage 2015: Choosing a model grade?

We are looking at buying a Kia Sportage and was wondering if is it worth the extra money for the SLi over the Si premium to get the extra features, particularly the reversing camera, as a review on CarsGuide said the small rear windows makes it difficult to see out? Also does the all-wheel drive on the SLi make the car handle better on-road?