I had a bad experience with Cooper Discoverer AT3 4S tires. They look great, and performed well for the short time I used them. But on pavement I sensed a buzzing vibration in the steering wheel at all speeds that I attributed to the tread lug spacing. They were balanced properly. I had replaced the stock tires at 20k miles, which rode very smoothly, with the Coopers and was surprised at the difference in the road sensation. I really wanted to like them since they seemed great from all the research I did. I used them for a month, about 1000 miles, and just couldn’t get used to the feeling.
So I traded them in at the tire store for Michelin LTX AT2 tires. They ride much smoother on pavement and have performed really well in dirt, mud, and deep sandy roads.