Ok, I have a rack from RBI and set it up on Thursday. I only have one snake in the top tub, the middle and bottom are going to be filled very shortly.

I have my Helix set at 93, I have a digital temperature gauge that reads 96.1. The probes are right next to each other taped directly to the heat tape just off to the side so the tub doesn't hit it. The two empty tubs are ready to go with hides and a water bowl along with aspen for bedding. I took some temp readings with a RBI 205L heat gun from underneath each hide and this is what I came up with:
Top: Hot 89.6 Cold 83.4
Middle: Hot 95.1 Cold 84.9
Bottom: Hot 93.9 Cold 82.1

Now the hide on the top is different than all the rest. So I am going to say that once I change that hide to match the rest I can turn the Helix down a few degrees and the temps will be pretty consistent.

Those of you that use heat guns to measure your temps, how do you do it? Do you have problems with the aspen moving around too much causing too high temps? I think I'm just being paranoid but I figured I'd ask what everyone else thought about this. Thanks.