I've driven the new Rio. No Rio5s available; only sedans.
Driving impression- compared to others in its class, I thought it was the best. It feels bigger than it is in terms of handling. The xA has a very firm, even harsh, ride. The Aveo's ride is too soft and leans heavily in turns. the Rio is the perfect comromise between the two. Very much in control, but you don't feel any harshness. The AT shifts crisply but does not jerk you around; the engine whines on heavy acceleration but is much quieter than the xA on moderate acceleration (like the dreaded freeway onramp downshift). The interior is definitely on a budget, but is a **** lot nicer than the 95 Aspire (Kia Avella in other parts of the world) I just sold. Better than the Aveo, too. Different from the xA, so I guess that's a matter of taste.
Price-wise, though, it's no bargain. There are lots of incentives and rebates on the 05 models but nothing buy owner loyalty on the 06 Rio. As a result, I can get a Spectra5 for less than a similarly equipped Rio5. If that changes soon, though, I might buy the Rio5 over the Spec5; I honeslty liked it better.
The biggest drawback to me was the rear seat. There is enough room for short trips, but not long ones for my six-foot sons. But seeing as it's mostly a commuter for me, I could live with that.