Well, I use sandboxes a lot more. Since I do next to nothing that isn't posted on this site, I have no reason to challenge myself with stupid objectives. Plus sandboxes already have all the custom scenery selected, so I don't ahve to go through and click every individual support piece for Jcat's, or whatever else I'm using. The onlt downside to sandboxes is that you can't toggle the fence around the park, or change it's style.