I've just started going back to graduate school. It has been difficult to find electronic copies of my textbooks. So far, I've only had one class where I was able to use a kindle ebook. It had it's pro's and cons.
First, I ran into drm issues because I wanted to be able to read it on my home pc, work pc, and iPad. The limit was 2 devices

. My feeling is that I should be able to read it on as many devices as I want as long as its one at a time.
Second, while it was nice to be able to search the text, some of the diagrams, even when zoomed to fit the screen, were fuzzy and difficult to read.
Third, the Kindle app does not show pages. It shows "locations". This is because it allows you to change font size etc. which would make the same amount of text take up different amounts of pages. This made it difficult to cite specific pages for references or look at a specific page for an assignment.
Fourth, the Kindle app would do funny things when jumping back and forth. For example, I would have the iPad turned to landscape orientation so I can see two pages. I would be reading the page on the right and the text would refer to some fig. which would be a hyperlink. You click it to view the figure and then click the back button to return to your reading. The problem would be that your page now changed to the left side of the screen and because the combination of the two pages now looks different visually, it disorientates you. I could find no rhyme or reason for this. Sometime, the page I wanted was on the left, other times, it was on the right. This isn't a problem if you use the iPad in Portrait orientation but then you can't see as much.
Fifth, I can't resell my ebook. For my next class, I'm going to go with the Amazon rental but it bugs me to have spent $80 on a book that I can't resell. If I wasn't getting reimbursed thru work, this would have been a deal breaker for me and I wouldn't have bought it.
Overall, I think I prefer the ebook but it's a tough call.