, agree that eheim heaters have stiff dial wheel, and the temp sometimes off calibration if place the heater at positions not according to instruction.
but I recommend eheim because it is well balance between the overall quality and the cost, and it is the best heater that I use through the years. most of the different brands glass tube heaters failed within two to three years...
I have a eheim 300 watt now into the 9th years of service still working without problem, got it from Ken's fish if I remember it right. I only power it up during the colder months though, about 5 month each year, and clean, dry, put in storage when it is not in use.
I feel sorry that you had bad experience with eheim heater, not one, but two, anyway, let's see what others can share their opinion which brand they have the most confidence with, and let OP make his decision.