Rancos, Johnsons are the two top of the line on/off thermostats and are perfectly fine. I have two.
Helix and Herpstat are the two top of the line proportional thermostats and many people prefer them for racks and incubators. I have one.
Both brands work well for me and do what I need them to do - which is to regulate my temperatures and protect my animals.
Hope this helps!
By the way, be sure you order the wired Ranco!