we use their thin fit 6" model out of necessity.  They kinda suck, but they are the thinnest, fully enclosed, speaker we could find.  The grills need to be glued in place or they fall off, but we install them on yachts so I'm sure they didn't think about that when designing them.  We don't have this issue with other brands though.

To my knowledge, we haven't had to replace any of them yet and we probably have 100 of them out there so far.