I've never had any issues in 15 years or more by using ST Fluids.
I have used their Oils, ATF-DexIII/Mercon & ATF-4, Coolant, Brake Fluid, P/S Fluid, Tubes of Grease and Brake Cleaner/Carb Cleaner...all with good success!
Though I DO try to buy the name brand fluids, lubes & cleaners on sale which beats W*M prices and I feel better when I do but, I don't loose sleep when I've used ST Products.