Yes, the hot side is controlled by it's own thermostat. I'm moving it just a hair and when it's turned down enough to not get to 100, it doesn't get to 90 on top of the glass. It's really frustrating. I assume it's because it's an on/off thermostat and a bigger pad than the cool side. I hear it swings 3 or 4 degrees in either direction before it turns on or off and if this is true, it explains my problem. I don't know why other people are using it successfully, maybe it's the pad size or maybe some people aren't seeing it at the max temp? The cold side also swings but it just doesn't get as high because it's a smaller pad and set lower.

Anyway, my herpstat should be here today. I hope it solves the problem