Mine didn't lose power but it feels like the brakes are stuck and the truck feels heavy. The brake pad life percentage also went down to 15% at only 6500 miles. Even after them having reset it to 100% when I took it in at 3200 miles and 65%. WTF. They drove it and of course , they can't feel anything. I drive this everyday. You don't feel if you drive it around the dealer. Only until you've driven it on a daily basis but it feels like I'm permanently towing something. But anyway, I first took it in at 1100 miles just in case I have to file lemon.
https://www.gm-trucks.com/forums/topic/223508-brake-pads/?tab=comments#comment-2251844