We used Sunray last trip and I was very pleased. I got a bit of a discount, ask for the Mousesavers or Mouseforless discount and I think they give you 10% off or something. The grocery stop was included in the price, some places charge you extra. They gave me a nice list of what food was in what aisles, and I had my shopping list ready ahead of time so I was easily able to get done within the 30 minutes. I have absolutely no idea where we were, but there was a liquor store in the same strip mall - that was a necessity for my parents!
It was a great experience overall, we're using Sunray next trip too, even though we'll be flying into Sanford so it is more expensive, but to me it is still worth it.