Which one should a Mac user choose?
Gerry, I am a Mac user and I was facing that same question.
It seems to me there are too many hoops to jump through to use a Sony. I saw a Sony reader at Best Buy and I like the screen and the price but, software aside, I don't like being bound to Sony to buy books. Sony is not a bookseller.
I have some reservations about the physical layout of the Kindle, even though it has some really neat abilities.
I have placed an order for a Cybook. I wanted simple operation and I did not want to be tied down to only one bookseller. I read a lot of public domain ebooks and I wanted to be able to import txt and html files natively and not have to rely on proprietary and/or third party software to convert formats. That is why the Cybook won me over.
I am hoping that electronic newspapers and magazines will become popular enough on Kindle that the publishers will branch out and offer editions in other formats through the independent ebooksellers.