Until now, there have only been two hybrid architectures: Toyota/Ford CVT, and Honda IMA. The Sonata provides a third option, fixed gear ratio, single motor transmission. In three months, the Sonata hybrid made significant market penetration against the Ford Fusion and Toyota Camry hybrids.
Consumer Reports doesn't like the first generation, Sonata hybrid but that is just what we'd expect for any first generation car, hybrid or not. I have no doubt the infantile problems will be identified and corrected, probably retro-fitted to the existing cars. For example, the newest 2010 Prius "braking pause" was just a software fix easily handled in normal service calls.
My understanding is it has pretty good highway mileage and might be a good option for 'road warriors.' My mom saw one at the dealer and remarked about the automatic, solar shields, something Oklahoman's are well aware of for cabin heat control.
No, I'm not interested in selling our Prius, 52 MPG is hard to walk away from but some folks prefer sedans.
Bob Wilson