I voted price. Before the Sorento, my wife wanted a Mitsubishi Montero. **** NO! We've had the Sorento for 2 years (20K miles) and haven't had any problems other than the clock going out. I've had my Mitsubishi Diamante for 3.5 years (41K miles, and this is the third one owned) and have had a few major problems with it that the stealership and Mitsubishi would not fix. I would have bought another Mitsubishi, but they blew that by not honoring their own warranty. I know the ropes and I know what should have happened.
It's kind of funny, you go into the Sorento/Amanti/Optima forums and everyone is happy about their purchase. You go into the Sedona/Rio forum and it's one big room of people yelling out complaints. Most of the complaints, to me, seem like more of a problem with the dealers than Kia. My Mitsubishi problem started at the dealer level and went up from there. I like the cars, and I think that overall they are good vehicles, but since the service was so bad, I'll never own another one.
The Kia dealerships around here have bent over backwards to please their customers, and I think that says a lot.