If you have ever taken the land boat ride, this is the walking version where you get to see most of what you would see on the boat plus a few things you dont. What is really the best part is that you get to walk through the green house(and fish tanks) at a more casual pace, be able to get right up close to a lot of the plants,learn how they are grown(including hydroponics) and stop to ask a lot of questions. You simply get a lot more interesting info from the guide on the tour (which are all college interns). One place you dont get to see on the boat ride is a couple of the research labs. We even got to sample some freshly pick vegatables from the green house. Its only about an hour or so and well worth the $12. You can book the tour in advance or take your chance and sign up the day of the tour near the entrance of SOARIN. There are many tours through out the day so you probably would have no problem getting on one.
Hope this helps
Lancer