We've stayed both on-site and off-site, and although we've enjoyed both types of trips, they are not the same vacation:
When you stay on-site, we use the parks more. We get up early and are among the first into the parks. When the crowds really start pouring in and the sun heats things up, we go back to the hotel for a long rest, then return to the parks for the evenings. With the parks so nearby, we tend to go-go-go constantly. We love that we don't have to drive our own car (or get into a hot car, or get lost). By the end of the trip, we're exhausted, but we've seen and done as much as possible.
In contrast, when we stay off-site, we have a more relaxing trip and more family time. We still get up early, but it's harder to get to the parks as early. We tend to make lunch our big meal, and we sit down for at least an hour to get a rest; still, we don't have the stamina to stay late like we do when we go back to the room for several hours. More than once we've said, "We'll go back to the hotel, eat lunch, then come back for such-and-such this evening." More often than not, by the time we're back to our room, showered, someone's watching a movie . .. we end up saying, "Oh, let's not go back." We tend not to go to the parks every day, but instead we enjoy the off-site pool and cook big meals together. We hate driving to and from the parks, but we hate coordinating with hotel shuttles more. The extra space in which to spread out is nice, but it isn't a must-have. By the end of the trip, we've had lots of family time and relaxing time, but we haven't done nearly as much.
Both are nice, but do expect off-site to be different. For the price difference you're describing, I'd definitely choose off-site this time. I think the big difference is that you're looking at the prime summer months.
I will second another poster's suggestion to bring your crock pot. I'd bring ready-to-dump crockpot meals in ziplock bags. That'd give you something good waiting for you every evening and would garner more savings.
When you stay on-site, we use the parks more. We get up early and are among the first into the parks. When the crowds really start pouring in and the sun heats things up, we go back to the hotel for a long rest, then return to the parks for the evenings. With the parks so nearby, we tend to go-go-go constantly. We love that we don't have to drive our own car (or get into a hot car, or get lost). By the end of the trip, we're exhausted, but we've seen and done as much as possible.
In contrast, when we stay off-site, we have a more relaxing trip and more family time. We still get up early, but it's harder to get to the parks as early. We tend to make lunch our big meal, and we sit down for at least an hour to get a rest; still, we don't have the stamina to stay late like we do when we go back to the room for several hours. More than once we've said, "We'll go back to the hotel, eat lunch, then come back for such-and-such this evening." More often than not, by the time we're back to our room, showered, someone's watching a movie . .. we end up saying, "Oh, let's not go back." We tend not to go to the parks every day, but instead we enjoy the off-site pool and cook big meals together. We hate driving to and from the parks, but we hate coordinating with hotel shuttles more. The extra space in which to spread out is nice, but it isn't a must-have. By the end of the trip, we've had lots of family time and relaxing time, but we haven't done nearly as much.
Both are nice, but do expect off-site to be different. For the price difference you're describing, I'd definitely choose off-site this time. I think the big difference is that you're looking at the prime summer months.
I will second another poster's suggestion to bring your crock pot. I'd bring ready-to-dump crockpot meals in ziplock bags. That'd give you something good waiting for you every evening and would garner more savings.