That change in the users libraries makes a lot of sense. Back when the uploads were public, it was basically an invitation to piracy. I don't think it was a big problem, though; I checked a number of times and I never found any commercially available ebooks. It was all minor stuff (similar to the way I have a copy of some Android apps).
I've tested their platform several times, and I really don't think you should use it. I think it's too heavily dependent on having a live net connection. Unlike most systems which can use the web (but don't really need it), txtr is crippled whenever you don't have internet access. That was not a good design decision.