The Garden Grocer was fabulous. I had submitted a large order for a week stay to WDW, needed groceries to feed 5 adults and one teen aged boy, and Garden Grocer delivered on time with all items nicely packed. They delivered the order to the Bell Services at my hotel right at the time it was scheduled.
Overall I'm happy with the service -- definitely not cheap groceries, but less than the gift shops.
Site was very easy to use, and was surprised at how well informed the company kept me about my delivery; in the middle of stressing about getting checked in at our resort there was no concern about our groceries because I knew exactly where they were at all times.