Dining Plan for 4 Days?

[disneynutt1225]

I was just wondering if anyone's done the 4 day dining plan and what the concensus is on DL's dining plan in general. We're going for 8 nights for our honeymoon, but only have 4 days in the park (figuring we could add more days on as needed). Is the dining plan something we could add on when we get there if we so choose or is it only available before we go? Any help greatly appreciated.