I've been buying only Big O tires for years, but a new policy cost me $120 to replace a tire that should have been free under what I thought was their warranty.
What happened: Major blowout on the freeway, shattering 1/3 of the sidewall and splitting 1/2 the tire from the tread. Changed to spare, brought it in to Big O the next day and asked, "What can you do?" they said, "You're under warranty, free replacement" and sent me to a neighboring Big O that had the tire in stock. There, they replaced the tire, then charged me $120 saying they have a new "Run Low Tire" policy that doesn't cover any damage whatsoever.
Sounds like BS to me and a easy way for them to reneg on their so called warranty.
Store: Highland CA, Tires: Legacy Tour, Bought: Apr 06, Miles: 25,000. This was the second freeway blowout on those tires...
My recommendation is not to buy tires there - you'll pay higher prices, get tires that blow out, and be serviced by a dubious warranty.