Yes, they are flat and can roll up and down just like the Factory intended it to be.
Just on all the side windows alone, I saved 25 lbs. The rear glass of which I have not installed yet is another 10 Lbs or so when replaced with a Hemi style Corning tempered glass. If the rear is Lexan, that could be another two pounds or more shaved and money saved as well compared to the Corning.