My wife and I had been here about 10 years ago before we had kids. This time we came back with our 4 and 6 year old boys, and boy, did they love it. The pavilion features both current tractors and machinery from Deere, as well as some classics from the past. Included in the "classics" is the ultra-rare experimental "Dain" tractor of which only 100 were made in Moline in 1917, when Deere was looking to get into the tractor business. Instead, Deere purchased the company that made the Waterloo Boy tractor (also represented here) and ever since most large farm tractors have been built in Waterloo, IA
Most of the "new" tractors kids were allowed (and encouraged) to get up and inside the cabs, which our boys really enjoyed. Besides standard farm tractors, they had a good assortment of construction equipment including an excavator, wheeled loader, and the like, and also some smaller lawn/garden type tractors and gators. Our boys could have stayed/played there all day if we had let them.
Next door is the John Deere store where you can buy just about anything that has the Deere logo on it, including a huge assortment of toys. We had just come from the Ertl outlet store in Dyersville, IA where the prices were somewhat better, so we didn't buy anything. There is no fee charged for the Pavilion.
The only downside was that we hadn't realized they had closed the John Deere Collectors Center which used to be just down the street and featured even more beautifully restored old Deere tractors in an environment that looked like a mid-50's Deere dealer. Too bad.
If you go to the Pavilion and enjoy it, you might consider going out to the Deere headquarters where they have a similar show building of equipment that kids can also get up inside.