GardenGrocer.com was very simple to use for our vacation grocery order. The website was easy to navigate and comprehend and ordering was such a simple process. Our order was shipped to our hotel within the requested time period and was then brought to our room with our luggage (which I am to understand is not the typical order or events, but it happened this way for us, so we didn't even have to go obtain our groceries - they came to us!). We will definitely be ordering from Garden Grocer for any future Disney trips.
This was my first time using a grocery delivery. When we arrived at our hotel my order was there. I was also sent a text and received a phone call to let me know my order had been delivered. I would definitely recommend using Garden Grocery if you are vacationing in the Orlando area to save yourself a little money over park prices for water, drinks, snacks, sandwiches etc.
I do not think any type of improvements need to be made. Was super easy and it appears you have perfected your service :)