I wouldn't place any value on anecdotal evidence, one way or the other. The usual routine seems to be someone griping about breakage of their device(s), followed by a bunch of people defending the quality of their device(s). Either way, the sample is very much self-selecting and ignores a lot of variables.

Likewise, I don't really place any value on people making claims about the build quality. They tend to fall into the heft is better and rigidity is better camps. Neither is an actual judgement based upon failure rates nor objective (and quantifiable) tests. They are just subjective claims about how a device feels. Of course, I don't blame people for doing that. How many people want to spend loads of cash on devices to perform proper tests?

All that I can say is that, based upon personal experience, Kobos seem to be sufficiently durable for their intended use. It would be nice if they were more durable, but that isn't going to happen until readers ship with screens that don't have a glass substrate.