Hi guys I have a Brinsea octagon 20 and a Hovabator 1602 with circulating fan have to admit I paid a lot more for the Brinsea 20, but the Hovabator seems to hold humidity levels more consistently then my Brinsea ATM. I am hatching turkey and chicken eggs.
I have read many helpful posts from BYC. Love this site, I am currently new proud hobby farm enthusiast I have chickens, ducks, and geese. I am currently experimenting in incubator hatching with some bourbon red turkeys and some cream leg bar and Bielefelder chickens. I live in Manitowoc WI
If you have the wherewithall, the Brinsea's are hard to beat.
Otherwise, for a styrofoam incubator, I'd lean toward a Hova-bator circulated air model.
You can likely find used units of either design on CL or Ebay