Hi Ronald, welcome aboard.
I would say that if you are going to spend much time in extreme climates of hot or cold, it would be a good thing. I am definitely going to order it with my 19' as I do want to use it at or a bit below freezing some times. I also am forgoing the A/C at this time and it will help keep it cooler on those really hot days. I will be adding the thermal windows as well. Of all the optional features, I would say that this is the most important to me.