I love it for controlling the heat. Hated it for controlling the Humidity, but for heat I don't know if I could do it without it. It keeps things perfect in my terrarium and the drop in temps is consistent every night which is healthy for my frogs.
For humidity control i use a MistKing Timer. It is amazing. I spent about 3 days logging when I misted, what the RH was before I misted, and how long it took me to boost it back up to where I wanted it. I used that log to schedule the misting of the terrarium and now the timer does all the work. I still spot check the Temp and humidity daily, but it is nice knowing the frogs are all happy and comfortable while I am at work.
Edit : wanted to add. I wended up going with a 100w Ceramic Heat emitter because it could get the temps up where I wanted them faster and allow the CHE to be turned off more often. It also helped with recovering from the night temperatures more rapidly. I have a 18x18x24 eco terra.