I don't remember if somebody already said this, but when a bullet is stopped by plexiglass the glass shatters and sprays little shards of plexiglass out. Lexan doesn't do that. So, it is superior and surprisingly, it isn't that much more expensive. Still, you'll see them combo plexi with lexan in professional bullet resistant glass. Usually though, the plexi is sandwiched between lexan. I guess it saves a little money.