I'm a 25-year customer of DT, and I've always been "relatively" pleased with the results of each visit. Yeah, I've had to return for a re-balance a few times, and on two different cars, raised h*ll because they damaged expensive, painted alloy rims. To their credit, though, they always repaired them.
This latest experience, though, began about two weeks ago. I've been running Pirelli Scorpion Verde Advantage II tires on my 2014 Buick Enclave, and totally loved them - smooth, responsive, great gas mileage, and they never failed to balance well. Noisy as h*ll, but great tires otherwise. Due to Covid, over the following 3-4 years I only put about 30K on them (I'm retired and have few occasions to drive long distances). They carried a 65K treadwear warranty, but they wore down to 4/32nds during that time. My DT Store Manager gave me a prorated mileage credit on 4 new Scorpion Advantage +3 tires, a newer version of my other Pirelli's. They were great, but only under 60mph. Above that, they vibrated the whole car. The same store rebalanced them twice, including road force balancing, without improvement. The store manager then installed a second set of the same tires. But, after the initial balance and one rebalance, the vibration was still there. Today he installed a set of Michelin Defender LTX tires on the car, but they vibrate just like the two sets of new Pirelli's. I'm at a loss, and so is the store manager. My original Pirelli's ran perfectly smooth the day DT replaced them. After that, it's been nothing but vibration.
Tomorrow, I'll be visiting a different nearby DT store. I called that store manager today and described the issue in detail. He offered to put the tires through their own inspection and balancing, so I will just have to go from there. My immediate suspicion is that the first store has either a balancing equipment problem, or a balancing personnel problem. At this point, it's impossible to determine which. I'll post back after this second shop does their thing with these Michelins.