Sorry I've never heard the Dynahi. From what I hear you can't go wrong with either choice.
I can tell you that the Thunderpants sound sublime on the Beta22.
I know I keep shilling Hyundai, but the new Sonata is a real looker IMO, and is getting excellent reviews.
Hyundai Sonata: Safe Family Cars - Better MPG than Camry or Accord | Hyundai