Exploratory is like stepping back in time in some ways, we enjoyed it. There's some fun things that your four year old will enjoy there too.
I don't have input on the others but definitely check reviews posted for some thoughts on those (or response in your post either/both).
if you consider Baraboo with the Circus there's other things to enjoy in the area and you can gauge it on what you think might work traveling with a four year old:
www.savingcranes.org you don't have to stay long and it's a nice walk around outdoors
http://www.wisconsinbigcats.org/ near Baraboo
Parfrey's Glen/Devils Lake State Park
smithsonianmag.com/travel/The-20-Best-Small-… Baraboo made the list of 20 best small towns in America.