They offer quick turnaround and very competitive pricing. Case in point: I had ordered company-shirts to be silk screened with our company logo and comparing our order this year with the one made previously, it was actually cheaper! We ordered more this time too! The task was completed in a week. Very good customer service. Our orders are rather small between 15 and 17 shirts at a time, so it's a deal.
PROS: great pricing; quick turnaround
CONS: limited choice in t-shirt colors