I bought my Rio with 73 miles on it. I've only had it for about 2 weeks, but so far I'm loving it. The Eco feature is hard to get used to, but it's a really neat thing once you're accustomed to it. It's got a good amount of pep to it, actually. I love how spacious it is inside. I'm over 6 feet tall, and I can sit in the backseat (and front) very comfortably. The little features like the folding side mirrors are great. The inside and outside don't feel cheaply made at all. I am thoroughly impressed with Kia's work on this one.
Power folding side mirrors
Eco- car actually shuts off at red lights, etc.
Auto Stick (manual override)
Back up camera (reallllly helps with parallel parking!)
Lots of knobs on the steering wheel. Like it.
I wish the EX had a moonroof. I'd like the SX, but I really am a fan of the Eco feature.
I also wish that the side folding mirrors would unfold when you put the car into drive. (sometimes I forget to hit the button to unfold)