Try again. It has EXACTLY the same air bag setup as the current Sonata. Dual front bags, front/rear side head bags, and front seat-mounted side bags. The only "safety" things the Sonata has that my Accord doesn't are stability control, EBD, TPS, and auto-headlamps, none of which add weight or improve the safety of the vehicle in an accident.
And since we're talking two cars that weigh almost exactly the same, I'm really not sure what point you were trying to make regarding Hyundai's suspiciously low performance.
As for the past, the Genesis V6 coupe has consistently performed far below its claimed power-to-weight, too.
If the turbo 4 can deliver on fuel economy, it will still be a compelling choice. Just not as compelling as if it could actually do the ~6.0 second run to 60 MPH it should have been capable of given their claimed power.