I think iReader is better.

The difference between iReader and kindle is not that big. The configuration and style are similar. It’s just that the appearance is a little different. It depends on personal needs. I use iReader children’s reader. The style is what I like. It’s very fashionable. It looks quite grand and has good texture. It’s easy to use. I used kindle pw3 before and it felt useless. The screen was small and it supported few formats.