I'm a straight shooter--I call it as I see it. This so-called firmware replacement is very poorly done:
- it has lackluster support for formatting
- it is extremely flaky and slow (at least on my 300, several people with 300s have said they could not get it to work at all)
- it cannot recognize pre-installed books, you have to place copies of your books in a special folder
- it has no support of CSS stylesheets (at least in ePub)
- it is not a good replacement for Sony's firmware
For the record I installed several ePub books recently purchased from Sony both with and without DRM. None had images except the cover, and none were more than 300KB. None were readable with this replacement firmware, unless by readable you mean look like a TXT file with no formating.
I suspect that those who are so exited about this replacement firmware either are connected to the designers thereof or perhaps are so new to ebooks that they cannot objectively know good or bad firmware when they see it. I've owned 5 different Sony reader models, 2 Kindle models, and an Aluratek Libre, and more PDAs with ebook reading software than I can possibly remember, so I know what is good, acceptable, and bad when it comes to ebook reader firmware. This replacement firmware is terrible and in its current state. I suggest they spend a long time polishing it before even thinking about releasing it. I will continue to warn people not to waste their time with it.