Re: Tire question
It's the tires and re-balancing may or may not fix it regardless what equipment they use.
I had the vibration with the Fortera's and had them rebalanced twice and it never was eliminated. When I changed over to the 20" Latitude Tour HP's it went away completely. In the interim, when I tried the Yokohama's I had a similar vibration but at a different speed. Nothing changed but the tires, they were all balanced on the same machine using the same wheels and vehicle.
Basically you nailed with your last comment, the Goodyears are not as smooth or vibration free as the Michelin's.
2012 Grand Cherokee SRT8 Black/Black