Can't say about the kindle. The wife has the color nook and gets ton of free books for it. You save them in pdf. format and transfer them back and forth however you want. You can share with anyone who wants to read it on a pc or nook.
Also, with the Color Nook, I followed simple instructions online, used a 32GB micro SD card, and "rooted" my wife's Color Nook and now it's a fully functional tablet for $200. I don't know what a Galaxy Tab is, but apparently it's $500 and doing what I did free, well, I had the 32GB card (worth $40 - $50?) and she has both a Color Nook and a wifi only (no phone service or contract) version of the Galaxy Tab. The geeks say the Galaxy has a faster processor but the Color Nook has a superior graphics setup, so they even out.
I'd say my wife has read well over 500 books on her original Nook I bought her and never paid a dime for any of them. It has only been recently that Kindle has had the ability to "borrow" books from libraries. Back when I was comparing the original Kindle and Nook, I had to scratch my head and wonder why anyone would buy the Kindle and fork over $25 or so for each new release when you got them free with the Nook. Simple math says that, if I would have bought my wife all those books she has read, (which I obviously would not have - she would have just have had to do without or go to the library and physically check out the book), the buying the Nook over the Kindle has saved me around $12,500!
Take that fact along with the free tablet her Color Nook has become, and I'm positively a Nook kind of guy.
I'd have to think that is why several other companies are scrambling and Kindle keeps dropping prices.
Either way, we as the consumers win. Although the screen was a bit smallish, we watched "Horrible Bosses" last night on her Color Nook in tablet form. There again, laying in bed with the Nook right in front of you, you really don't need a large screen. Whatever rooting is, it allows the Color Nook to have access to all the apps in the Android system and run the latest "Gingerbread" version of OS. Pretty cool for a $200 device. She's loading up on apps now. Manually setting her brightness, she gets about 10 hours or so of battery time like I get on my iPad 2. LOL, I just figured out a few days ago that the keyboard I don't use on my iMac works perfectly with the iPad and there are covers that both fit into neatly. I'm stoked, I feel like I got a free keyboard for my iPad 2 since I have never used that keyboard with my iMac.