[Noughty]

I did a reset once. You lose time settings in it - sync fixes it. If you are unable to connect to amazon account, when it's bad news for you. Date settings need to be sync, only time can be modified manually. Had a talk with customer support on that one and a few days with bad date (which messes with most recent view) since I couldn't connect to wifi then.
Now I can't remember if I lost books in that reset. Glad to know that in case this happens again I can do a reset without any fear.

As for freezes. Kindle support said that once or twice a day is normal. I disagree.

So far it had maybe 3 serious freezes, sometimes it doesn't turn the page when I click. I'm not interested in replacing kindle, if it become more frequent or annoying sure, but now not worth it.

This latest freeze would have been nothing, it just was at the worst possible time. That's why I wanted to clarify the danger of loosing books on kindle (I have them all on calibre, but while on a trip it doesn't help much). That day I did like 7 hours of reading, I would have been so lost and bored without kindle (the freeze happened about 15 mins in reading not after many hours). And that "book" was just a short txt file. I had to put some text on kindle and this seemed like the fastest way. Will need to figure out creating mobi files for stuff I need to read.