Plastic by far holds heat way better than glass but if heating isnt an issue I prefer glass.
Even than you can certainly heat glass tank but again way less watts heats plastic that much better.
I don't stack cages and the only issue I have in snake room is cooling it which is easy by leaving one or two AC ceiling vents open depending on time of year .
I like glass as like the view and find it easy to clean. While back my Ruthven king outgrew his 55 gallon and looked at Animal plastics .
GREAT cages but opted for a 75 gallon long (60 inches) that pet store was selling .
Glass is also better if you need high humidity (simply place acrylic/glass sheet on screen) because over time high humidity can cause problems with plastic cages .
I use both and prefer glass since heating isn't an issue .
