Sorry Costco.. you are still my favorite retail store that I can visit in person but Costco delivery SUCKS! I ordered something that was supposedly 'in stock' and had 3-5 Business day delivery. Arriving via UPS, I have now received two re-schedules that now has it arriving tomorrow. That would be 11 Business days by my calculations. Amazon prime 2 day has only once been 1 day late over 7 years of being with them. Therefore Costco may claim a lot of things but delivery isn't one of them!
http://www.businessinsider.com/costco-comments-on-amazon-go-2016-12