Since I wrote my initial review, including the follow-up to include Stanza, I have realized that there were a few key features that I neglected to include. They are Annotations/Notes, Highlighting, and Dictionary functions. The first two I don't use much, but it occurred to me that other people might, and so they should be discussed. The Dictionary function is really neat and once again supports iBooks and Stanza as the top two readers on the iPad. Before I get into that, let's review what each app does or does not feature in terms of these three things.
iBooks does not allow for notes or highlighting of the text. You can bookmark sections of text which is a poor man's substitute for highlighting in a pinch, but other readers clearly do this better. iBooks does have a dictionary where you can get to a definition in two taps of the screen. It's also the quickest app to pull up the relevant information.
Stanza does not have highlighting either, but does feature annotations. Oddly enough, I found that when I added notes, it would kick me out of the app once I left the note. The same was true for deleting it. While this is a big issue for now, I am sure it will be fixed in a future update. The notes are hard to pull up once they are placed in the text, so I'm not that fond of this feature in this app. Stanza is the only other app to have an internal dictionary. It's a little slower to pull up than in iBooks but only takes two finger taps to bring up.
Kobo, is one of my favorite apps from an aesthetic point of view. However this app does not feature any notes, highlights or dictionary functions. Swing and a miss! I know they were going for a barebones, elegant design, but they really could have done more in this area.
Kindle has no dictionary, but does feature annotations and highlights. I found Kindle to be the best at being able to pull up notes placed in the text. A little blue box marks the presence of the note, and you only have to tap on that to see the note.
B&N has annotations and highlights. However the former are hard to access, much like with Stanza. B&N does have a dictionary function, but you need 3 clicks to get there and then you taken out of the app and placed in Safari! What a waste.
Since I don't use notes or annotations, I won't comment on their usefulness specifically, but I do want to raise a point about the dictionary. Ever read a word in the book where you don't recognize it, and you want to know what it means, but the context is enough to get you by and you just don't want to pull away from the story to look up the word? Basically any attempt to define that word is a pain in the ass, so by default, you just keep moving along. The dictionary function changes that. You can look up a work quickly (especially in iBooks) such that it doesn't ruin the flow of the story. I really enjoy this feature and use it a lot, especially as I find myself reading classics from 100 years ago or more that use pieces of language that are quite uncommon in today's vernacular.
Hopefully I've covered all the salient points of the apps by now, but if I've missed something of interest to you, let me know and I will add that to the review.
Well, one last thing! A co-worker showed me how to change the brightness in Stanza. All you need to do is swipe up or down the center of the screen. Down to darken, up to lighten. Pretty cool!
Thank you for posting all this great info with follow ups. It is much appreciated. High fives and gold stars for you.