saw one on the highway this weekend... and i was dissapointed (not that i care much about kia to begin with). it looks like it's trying to be an alternative to a more expensive car, but i don't know if it'll fool many. maybe it's a good buy, but at least to look at it's out of it's league. design isn't very cohesive... the front doesn't go well with the sides or rear. meh.
Oddly enough, you're only about half right. Kia and Hyundai share platforms with the Amanti/XG and Optima-Magentis/Sonata, but not the others. The Accent and Rio are on two unrelated platforms. The Sorrento and Santa Fe do not share platforms...as a matter of fact, the Hyundai is unibody (related to the Elantra) and the Kia is body-on-frame.