Ceramic glass is typically for masonry fireplaces because of the heat of the fires. People tend to build bigger fires in masonry fireplaces. You are able to burn with the doors closed however it is advised that the grate and logs be at least 4"-6" from the glass. We do caution against building bonfires and never burn cardboard or other garbage in your fireplace. It would seem like common sense but we have seen what those kinds of fires can do. Because of the weight of ceramic glass, the doors are sold as cabinet style.
The easiest way to tell the difference between ceramic glass and tempered is in how it breaks. Tempered glass will shatter where as ceramic glass will crack and break in big pieces.