Well, there are also multiple reports of the glass breaker on the Contego working successfully breaking glass. Perhaps this will ease your concerns. However, If it doesn't and you are concerned and require a dedicated glass breaking tool then by all means get something else that inspires more confidence for you. Noting wrong with that and what I would do. I'm just not prepared to condemn the 810 as not being up to "hard use" (whatever that is) because of a few back spacer failures out of who knows how many made.
Yeah, I think there's about as many reports of successfully breaking glass, as there are of breaking back spacers, thanks for the reassurance.