Snow mpg max controller accuracy?

I was wondering if anyone has checked to accuracy of the boost and egt readings one the controller? Just installed mine this weekend and removed the msd laser gauge that I had. I was seeing 1500* on wot now I'm seeing 1200* with no water. Also at idle I'm seeing 320* where I was seeing 400ish. The thermocouple is bigger on the snow kit believe 3/16" compared to 1/8" before. Only thing was changed was air horn and snow kit. Now I'm starting to wonder which one was reading correctly?

I have a set of analog gauges on my truck, as well as the snow controller. They read as much as 100F different sometimes. No idea whats with that, or which is wrong. would have to take a measurement with a known accurate thermometer to say for sure.
When it comes time to shutdown, I go with the gauge that reads the highest.

The snow probe is good. Sometimes cheap gauges only are showing you the difference in temp between ambient and the temp it is registering, not absolute temp. Sometimes that can cause a discrepency.

For what its worth, I'm running a H&S Mini as well as a analog boost gauge.

The Boost #'s are within 1-2psi most all the time and the EGT between the Snow and the H&S can be 50deg +/- difference.

I dont figure I'm going to run it long enough at any given temp for the 50deg to hurt anything so I've never worried about it.