Overall, I am impressed with iBooks for iPhone. Yesterday I downloaded some free books, and was really impressed. I'm not much of a book reader, but I might buy a title or two. I'm impressed with the selection, as well as the affordability (compared to buying a hard copy).
Being able to search for text is another HUGE bonus for me. If my textbooks became available on the iBooks store, I'd buy them there instead of from our university bookstore (where the average title is upwards of $100 CAD). Searching the books would sure help with finding specific quotes, etc., for university papers.
I am on a 3GS and am not impressed. Seems to take a long time to load bookshelf. And already I have gotten an error prompt (below). It goes away after having the app open for a minute or so. I assume it happens because the app is syncing where I last opened the app and loading the content of the book.
I get the same problem on my 3GS. When I try opening the book a 2nd time, it opens fine. Sometimes it can take a while to load though.
the app is quite slow on my 3gs... i downloaded a pdf and winnie the pooh and it always gets stuck on some pages and takes forever to load
Once the book loads, it's fairly fast on my 3GS. But while it's loading, it is slow as heck!
Oh, come on. Like you've never downloaded a song or video off the Internet. Really?

What makes getting a book any less different? Smaller file size is all I can come up with.
Pirating is illegal whether it's a book, app, video, music, etc. As a musician, I understand what stealing music does to the artist. In a world where stealing music (or books) is easy, no one wants to pay for it anymore; makes my life that much harder, as it does to other artists.