It also depends on what time of year you're going. I've been during the middle of peak season when we had to be there right when the opened to avoid crazy lines and I've also been at times like September when we've been able to almost walk right up at 6:30 PM and have no problem getting a seat. So, if you're going during a buiser time, I would recommend off-peak eating times, but if you're going during a slower time of year, you have a little more leeway with when you want to eat.