they charge premium price for low grade tires. Their service varies depending on the location and you can still get their service if you buy from tirerack.com but you also get a nice set of tires.
What lowgrade tires are you talking about? They sell the some of the mid-grade and higher-end Bridgestones, Goodyears, Pirelli, Michelins, etc. that everybody else sells. If you want to go down to the low end, they'll sell you that, too. I've bought $85 Falken Ziex's from them in the past that melted off in about 17k miles and bought $160-$190/tire Bridgestone RE960 Pole Positions and Michelin Pilot AS from them that last 40k+. Each time, I found a lower price than they were selling them for and had them match the price. For All-Season high performance tires, they sell the same highest rated tires that TireRack sells (based on their survey results).
In the long run with warranty, free balance and free rotation when need at any store it's worth the prices at discount tire.
Haven't been to a location that didn't treat me well. And they show you the options available to you before you buy; I've bought low-grade tires from 'em on a car I wasn't keeping too much longer, and I've bought higher quality ones too.
Another Discount Tire proponent here. Got them to knock $80 off my tires and the customer service was great
