All excellent points in the above. The electronic lock method can save quite a bit of time.
Upon arrival at Windsor Hills, the guard will look over your documentation, as mentioned above and give you a card that will open the gate for subsequent entrances. If your reservation starts Saturday afternoon, if you hit it wrong, there could be a lengthy line for the guard checks. Each car takes a few minutes and I've seen over 10 cars in line at times on Saturdays. Potentially not great if you have groceries that need to get in the refrigerator.
I also prefer the Publix mentioned above. Its a few miles away, so its slightly longer in distance than a couple of the Publix's on 192, but its a quick ride. Leaving Windsor Hills, you'd just make a right on Old Lake Wilson Blvd and go until you get there...it's on the right just past a traffic light. 10 minute ride, if that.