Better Bottles ... will not shatter.
No but they will stress and crack at the most inopportune times spilling precious homebrew everywhere. If I do plastic, its a nice thick walled bucket...
My LHBS has a Better Bottle on display with a crack at the bottom where the wall meets the bottom. The crack apparently was due to chemical stress or some other environmental stress fracture. It has a sign on it reminding you not to store chemicals (PBW, StarSan, etc.) for extended amounts of time; just clean and sanitize and get the chemicals out and let it dry. Always put water in first, then the chemicals, etc. I know I get lazy and let my carboy sit for days with PBW until I get around to cleaning it. I guess if I ever replace them with Better Bottles I will have to make sure I am careful about that.