i just got the hydrofarm MTPRTC thermostat today and it works like a charm with a +/- 2 degrees off. I know this because my Acurite thermometer probe sits directly on top of the UTH on the glass and it reads the temperature which is +/- 2 degrees from what the thermostat reads. The probe to my thermostat is taped at the bottom of the UTH under the tank. I did not tape the probe itself but the wire.

I test drove my UTH without a thermostat and it my Acurite thermometer read 148+ so its a MUST to get a thermostat. (my bp was not in the tank at the time)

I was in the same situation as you, I bought a Zilla thermostat at Petco for $55 and it was awful with a +/- 10 degrees different. Used it until my hydrofarm arrived in the mail.

Good luck with your setup