The CNN Studio Tour is an okay thing to do once, but I can't imagine wanting to repeat the experience. For one, photographs of any kind are disallowed. The whole point of things like this, it seems to me, are the photo-ops, so that's a strike for the tour. Second, much of what you see is accessible free of charge (other than being on the catwalk above the newsroom, which is not accessible to the public). And third, of the three times I've done it (taken visiting friends/family), I've had horrible tour guides who essentially learn the spiel but can't answer any questions they're asked.
If you've ever seen a newsroom, you can skip the CNN Studio Tour. Newsrooms are the same everywhere--lots of people on computers, frantically scrambling around and drinking coffee--although, obviously, the stage is grander at CNN.