As a present I got the kindle 4 last week. As "The mysterious Island" from Jules Verne is one of my alltime favorites, and I haven't read it in english so far, I downloaded it, and I am now at 15% -> this will be the next book reviewed!
So far I like the system, and I like the reader itself. What I don't like is, that there are no pagenumbers, but only the percentage you have read so far. I understand why that is, because you can change the font size and the font itself, but all the same, I would like it better if I could see the page number!
The loading works with an micro-USB plug, either via PC or via power socket. The first time load via power socket took about an hour, this has been 3 days ago and although I read very much and played around with the kindle even more the battery is still full.
The "picture" is refreshed around every 7th page, during the other pages only the lines are refreshed, what leads to "ghost letters", but is not really a problem, apart from when you sit under direct light.
So far I am really happy with the kindle, but I don't think, that I will read everything now only on my ebookreader (I still have about 50 unread books in my "unread" shelve). But there are so many classics one can read for free... I really will exhaust the possibility of downloading and reading them for free! [I don't have to much space left for new books, so I will focus on books I really have to have in the physical edition, when buying new books]