Took the Zion National Park "tour." Bill drove us up there. He talked the entire trip, providing us with useful information and entertaining trivia.
We were picked up and dropped off at our hotel on the strip. Vehicle was a Ford Expedition, which provided acceptable room (we were in the 3rd row -- ok for a trip of this length but not longer)
Once we reached the park, he showed us on the park map which tram stops to use and which to skip. (guides generally aren't permitted in the park unless you meet National Park Service requirements, and you have to take the NPS tram to traverse the park in season.
We had 3.5 hours to ourselves in the park, which was about enough time to follow his recommendations and take a couple of short side trail hikes.
So what do you get for your $200? Portal to portal transportation, guide's recommendations on how to traverse the park, a decent lunch, & bottles of water. Your call if it's worth it. We thought so, since we didn't want to rent a car; also we got Bill's insights on which tram stops to skip in order to have more time at the better stops.