Many e-book devices in the market are imitating the paged view concept like in books. I see that some e-book apps added also scroll view as an option. Is there any study that which paging style is preferred by users? Comparisons will be also appreciated...
When I first started to reply to your question, I felt like I was pretty firmly in the paging camp, but as I researched and thought about your question more, I think I've landed in the scrolling camp.
Pro-Paging: Level of Control
I found an article that compares the "fine grained control" of scrolling, vs letting the user read the story. It talks about how too much control just gets in the way when you're trying to read a story. http://ignorethecode.net/blog/2012/11/01/pagination/
Note that this article talks about pagination in a clickable form - but I think that the current method of "swiping" to the next page (like in the kindle app) applies to what he's talking about much better. The swiping feels natural (as many of us grew up with paper books)
@Geobits made an excellent point below about refresh rates with scrolling, which would be another point for paging. Sometimes when you try to scroll back or forward in the content, you're left with a blank screen, whereas the paging feels pretty immediate.
Pro-Scrolling: Content Presentation
Another article that talks about paging being a relic and the benefits of scrolling. One of these benefits, which is sort of big, is that when you're not breaking content up by page, there aren't any strange gaps. Everything stays together. http://www.leancrew.com/all-this/2012/11/scrolling-or-paging/
Another point, although I don't have an article for this, is bookmarking and loading the book on another device. I've had many issues with trying to sync to the right page between devices where the page size is different and therefor there is more or less content on the page. I usually end up several pages off from where I need to be. I feel like bookmarking in a scrolling environment could and should be more precise and these issues of scaling the content should go away.
personally, I usually prefer scrolling - both because it is now a natural movement, and for the content presentation.
However, I'm currently reading a kindle book on design that has a lot of diagrams (usually far from the text that's referring to them) and it's helpful to me to think "oh that diagram is a few pages back" instead of having to scroll to get there.
Basically, (in some cases) it may be less manual movement to swipe/page back to another place. This isn't always true, (and the trade off is that sometimes I will see half a page of text, then an awkward blank space, and then a huge diagram). It would flow together much better if it was in scroll form. (It would actually be great if the fig references linked to the image or something of that nature).
Also, looking forward, fewer people will be used to paging through a book as more and more media will be digested online.
I think giving the user the option between the two is a great option, although, in the end, I think scrolling will win.