Many people do have thermostats, because you do need to know what the temperature is. I don;t have any experience with them (I cant get any until I find a job, which is a long ways away with my mental issues... haha) If you can afford it, perhaps you could buy both, and use one for the hot side, andone for the cool side. Or, use both in the middle to get an idea of how they get the temperature, and if one of them doesn't work as well or isn't satisfactory, take it back.