Thanks to all for the feedback.

I ended up with the Michelin MXV4 S8. So far they seem quieter, but I'll report back with more info, including mileage, after my next trip (in June).

I suspect the Yokohama Avid TRZ tires are even quieter, but since they are T rated, I was concerned about warranty issues (Toyota claims the warranty is void if the car is involved in an accident wearing less than V rated tires.) I'm hoping that when these wear out, there will be more V-rated choices with low rolling resistance.