I have used them all, haven't found one better than the next, just make sure to use a thermostat with whatever you have to regulate the temp.
I do have a suggestion for any of the "peel and stick" UTHs, though. Take a sheet of aluminum foil about twice the width of the UTH, stick the UTH to that and fold the sides over the top so it is completely wrapped. Use packing tape to stick it to the underside of the tank, this way you can reuse the UTH if you want to put it on a different tank or need to wash the entire tank, where water may get on the UTH, without damaging the pad or wires.
The foil won't hinder the UTH in any way.