Our friends recently purchased a Carnival. (They wouldn't have even considered Kia until we purchased a Telluride.) It's really nice. As people have said, it depends on your family's needs. We had three Honda Odyssey minivans from 2005 until this year when we bought the Telluride. The Carnival is nicer than the Odyssey, and somehow has even more room behind the third row.
We miss two main aspects of the minivan: One, our dog could get in and out of the sliding doors much easier, and had a ton more space between the first and second rows (he's a big dog, and getting older). Second, the minivan had way more room inside. Our kids are all teenagers now and we just took a trip to Colorado with all three. In the minivan, there was no need for additional storage. I could even fit my skis in back on winter trips, with three kids and all our stuff.
With the Telluride last month, we needed a roof box. Also, our daughter went off to college last fall. We got her there with the minivan, and had plenty of room for all her stuff plus three passengers. We picked her up in May with the Telluride and, even with the roof box and without my wife, we were still really challenged for space.
If the Carnival had an AWD option, we very well might be looking to trade. It doesn't though, so we'll live with the inconveniences of less space.