I switched from a cheapo non-proportional thermostat to a rheostat, then to a herpstat 4... Now I don't know how I dealt with constantly checking the rheostat... I"ve been seriously spoiled by the herpstat. And, since it has 4 ports, it'll be able to service the 2 racks I want to get in the future plus separate tank setups ,etc. I have had zero problems with the herpstat since I got it about 1 month ago.