Pros: Price, shop while you wait, appointments offered for install
Cons: understaffed during peak hours, many items not in stock
As others have mentioned, they're understaffed during peak hours. A great indicator of how busy they are is a simple phone call. If they're busy, they do NOT answer the phone. After waiting for 30 minutes the first time (to get a price), I called before returning the next two times (to place the order and to have the tires installed).
I bought a set of Michelin tires for ~$900 ($70 off with $0.01 install) ...the next best quote I had was ~$1250. Delivery took 4 days and install took less than an hour.
Rebecca and Billy were both courteous and helpful. If Costco's advertising a special, it's worth considering...just avoid going in during peak hours.