I say, as long as he is eating, drinking, going to the bathroom, sheds well, isn't sick, and isn't aggressive then he is happy and doing what he likes to do.
ummm, i got most of those, he hasent pooped in a while, and by a while i mean like almost 3 weeks, he is eating like a monster, he sheds fine, actually the last time he was in his hot side hide was when he was in shed, and i know this because i found his shed skin in his hot side hide. Dosent seem sick, has not shown any signs of RI or anything like that, i inspect his scales regularly for anything unusual, and nothing. Basically his love to be cold and the fact that he hasent pooped in 3 weeks is the only issues thus far. Hes never refused a meal.

And as far as the probe, its between the UTH and the tank, i had to mess with it to get the right temp to around 92, i set up the tank and the UTH days before i placed him in there, so i have the temps perfect. I still check them once in a while, and still the same, surface temps on the hot side hide in the 92.x's so says my PE2