I have had the kindle for a couple of months and am mostly satisfied. I am a little disappointed in not being able to get certain books. I would like to purchase the new Grisham book, but it isn't availble on Kindle. I have emailed them a couple of times and have never received a response.
Regarding, the kindle slipping out of the cover, I am more aggravated with the battery cover coming off too easily.
Overall, though, I enjoy reading on the device and find it less tiring than the hard copies.