Are heating pads for LCD screen replacements worth the investment?

I hate changing LCD screens (like most people) so I am looking for tools to make this task easier. As of right now I use my hot air station, and in some instances a simple hair dryer, to warm the glue and slowly remove the screen. I have seen these heating mats that you lay your device on and it will evenly heat the screen and device and they have peaked my interest. Does anyone here have any real experience with them? If so, are they worth the time and money to use? A secondary case use I have for considering a heating mat is to preheat boards for IC replacements so I am curious if these devices can be used double duty for both causes.
Very interested in your replies!

Hmm. I believe in theory preheat board + silicone pad= heating pad

It sounds like you are suggesting a board preheated and just putting a silicone mat on top of it?