Okay, I figured out the thermometers, I won't explain the details, but they are reading accurate now, and as for as the stick on ones go, they read pretty much the same, for example, if the didgital reads 91.5, the non didigital on reads 91. So I don't know why everyone says there crap because mine are quite accurate.

As far as the plastic Tubs go, the only reason we switched is because everyone was raving about how great they are and how easy it is to keep the temps up. But now, I 'm hearing a different tune, everyone seems to have the same problems with the plastic as they do the glass!
We had exact same problems with our glass tank, hot side good, cold side 70, then we added a CHE and it only raised it to 75, and that was with foam board inside and out side, a wood lid with 95 % covered to keep humidity up. So I figured, maybe the tank was just too tall to hold the heat down, so we switched to Tubs, but they are exactly the same for holding heat!
I will post pictures soon so you can see it.
We went back to the pet store and the guy said, as long as the cold side doesn't go below 70 and he has a hot side, it won't matter. Weather he is right or wrong I don't know.