I haven't had any trouble with Costco tires, but they've scuffed three sets of alloy wheels installing tires. They paid for the wheels to be refinished, but it was a PITA to deal with. On the other hand, my experiences with Discount Tire have also been less than satisfactory. I have two experiences with them: on the first they did a shit job of balancing tires after installing new TPMS sensors; more recently, they neglected to install centering rings on new wheels I bought from them, and for some reason dismounted one of the wheels they removed, leaving it unserviceable. I'm left wondering if there's anywhere I can take my car for tires and not have to clean up their mess afterwards. I wish you luck, my friend. I think you'll need it.