I finally fixed the vibrations on my 2014 Silverado by replacing it with a 2016 F150 yesterday. Yea I lost a lot of money in the deal but this truck is better than my Silverado in every aspect. Its drives so nice and best of all does NOT vibrate. Now I can finally sleep at night and not have to worry about all the BS GM was feeding me. I lost my arbitration hearing with the BBB as they sided with GM stating it was "normal operation" to vibrate at speeds above the posted speed limit. This has been such a horrible experience and GM does not give 2 shits, I will never own another GM in my life. Time to put this all behind me and enjoy my new non-vibrating truck! Best of luck to all of you still fighting this.
BTW for those worried about insurance going up for the alum body, my insurance actually went down $.04 /month with the F150.