I'm used to epub. I can modify epub. But overall I don't care.
I am not to keen on proprietary even if it offers advantages. Also I would not like to be locked into a subset of stores.
Still many people are happy this way and are reading more because of convenience. Good for them.
My main reason for having an epub reader is that in addition to a lot of choices, I can download a library book in the middle of the night if I want to. If kindle books were available in Canadian libraries I would get a kindle too.
I plan on getting another reader in the fall if there is anything outstanding on offer.
I am hoping it is a Sony, as I have been in love with at least two of them, but if Amazon comes up with something better hardware and software wise, then I will not let my prejudices stand in the way
Not that I actually need a better reader of course, as all of mine, even the Kobo's are adequate.
Helen