We used them recently in nyc and user experience was great. However once you do the math, a 10 - 15% markup on most products in addition to delivery fees, tips, (or prime) is simply too much if you use them on a regular basis. The annualized cost for a small family is easily north of $2000.

Now I know that "price is what you pay and value is what you get". So there are definitely occasions when I will use them. But I honestly doubt that most of their users realize the true cost of their service.