My first "tour" was with a group like that -- a week in the amazing scenery of southern Utah last fall. It's a great way to ease into the experience of immersive biking, and you get to travel light, and you have built-in companionship.
Now I find myself drawn more to self-supported touring, because I want to go more at my own pace -- I'm one who does like to stop and look around occasionally. Plus I like the satisfaction of planning out my own route.
There's still room for some organized trips in the future.