I read about a guy almost cutting his hand off in a glass carboy accident. The next day, my friend was shaking one with cleaner and it slipped out of his hands and when it hit it was like an explosion, big shards of glass flying fast and far, thankfully away from us. The next day I ordered two BB but hung onto my glass because I was afraid of scratches, etc. But I have used the BB almost exclusively for about a year and a half and have had zero problems. I am more careful not to let the metal part of the carboy brush to touch the side, and I quit using my powered carboy cleaner although it might be OK. Visually, it gets very clean without a lot of effort. I don't have the hole in the side because I use CO2 to transfer. I have one of their air locks but I end up connecting a hose to it and putting it into a bottle of water so I can see the rate of bubbles. I could see it for a very long secondary where you might let the ferm lock run dry, but otherwise not sure it is worth the investment. I have sold my glass and will never go back. I don't know how many time I nearly dropped the glass and I don't want to lose a lot of blood for it.