Another thing, that I don't really have much faith in is the mounting spot for the ring for key ring attachment. It is just 2 slots in the end of the plastic shell. The middle part that keeps the ring in place seems breakable which much bad folding action of putting it in & taking it out of your pocket. Also the way it snaps together is what keeps the ring from coming out of the shell by the force of the keys being bent to go in pocket, popping that end of the shell apart. I'm not attaching other keys on mine.
I've had mine attached to my keyring since I got it, and it's been just fine so far. You have to use a really small metal ring (that you then attach to a keyring), I think I mentioned that I picked one up at a craft shop for $2.00 (actually a whole bag of them). You're right, the little plastic tab could break off at some point, but I'm willing to take the risk for the sake of convenience. I should also mention that I've never had the shell pop apart, so far it's been totally solid.