Toyota Certified Prius v tires question

We bought my 2012 v Five this past December from an independent used car dealer; they put new Toyo Extensa HD 215/R17's on it. I run them at 48 psi front, 46 rear, and average somewhere around 40 mpg in our Cincinnati winter weather. The dealer told me that the front tires were new, but not the rear. The car had roughly 101,000 miles. I'm fairly happy with these tires in wet and snowy weather. My wife's 2008 sedan came with OEM tires (Toyo?) was pretty slippery in wet weather, so we replaced them with Goodyear Assurance All Weathers.
The difference was astonishing; the new ones are much quieter, and wet and snowy weather adhesion is vastly better, although at the cost of 5 mpg (45 down to 40, also at 48/46 psi). Nonetheless, my wife loves those tires, and I'd happily put them on again. The Toyo's on my v are better than my wife's OEM's, but not as good as the Goodyears. Nonetheless, they're good enough that I have no interest in replacing them.