In my opinion, it's not a vacation if I have to set foot in a grocery store. It's so nice, especially with young kids, to get into the room after a long, trying day if traveling and be able to relax and have what we need for the morning (like coffee!).
I used this service while in Disney World with my son in April 2016. I found the service very easy, fast and accommodating. I received my groceries as promised along with text and phone call to advise me they were at the resort as we were at the park when they arrived. The resort kept the cool items in the fridge for us until we returned. Great service and will definitely use again if we go back some day :)
So easy and so convenient!