I have been a longtime shopper at Williams Sonoma. They have the best quality cooking goods, amazing seasonal items, and delicious baking mixes, sauces, seasonings, and other things for the seasoned (or the less skilled) cook.
I recently signed up for an online registry for my recent wedding at William's Sonoma, and it was a fairly average experience; they don't offer anything remarkable. No huge completion discounts (only 10%; other retailers offer 20% plus additional incentives).
While their prices are high, I cannot usually find comparable goods for lower prices elsewhere. Sometimes I find the same product at the same price with promotion codes available.
Shipping is rarely fast and can be very costly. I believe that William Sonoma is one of those stores that charges for shipping based upon the price of the goods purchased.