I read magazines on my iPad and that is all, I find the bigger screen weird for reading books on. I would have been fine with an iPod Touch except that I need to show Powerpoint and video to my students. I use the iPad more for teaching than anything else and it does the job for what I bought it for. I did not buy it intending for it to be my main reading device.
But I have an uncle who has been quite happily reading on the Kobo app and considers himself to have now discovered the ebook revolution. My mom showed him her Kobo and he was glad she was enjoying it but said he was quite happy with iPad+Kobo. So to each their own, I guess