Brian, I have never done a real in depth comparison. I intend to but I always get to involved in the cook and forget, but it is similar but usually about 10-20 cooler on the lid therm. But, my lid therm is old, so it probably isn't accurate to start with. One of the biggest advantages of the Smoke remote thermometer is that it is so much more responsive. It displays the actual temp within a couple seconds where the lid thermometer is always way behind until the temp stabilizes.