Rancos work fine for racks, just gotta run it for a week or so to get the "in tub" temps where you want them just like any thermostat. You can set the ranco within a degree of where you want it to cut on and off. So this person that got theres up to 160 is very suspect to me. herpstats are definitely better don't get me wrong. but if you want to save 80$ a ranco will do the job just fine. I have one of my racks on a ranco and haven't had a problem ever with it, A lot of people use rancos, if they were bad you would see it all over this forum.