I have bought my wife a Kindle for Christmas - the best bit of kit I've ever invested in. Why? Because it's the first electronic gadget that's ever tickled her fancy, and for God's sake, it cost £150 - that's a lot of money up front to read a bl**dy book! Point is, she will never again be able to point the finger at me for exhorbitant spending on gadgets! So as I say, I reckon it's money well spent!!
On the practical side, it really is clever. Already, we have downloaded about a dozen books - which otherwise would have gobbled up a lot of room in our suitcases and been seriously detrimental to our baggage weight allowance on our January holiday. If she reads them all, she can browse and download as many more books as she likes from the beach. And I will be able to get a daily e-newspaper downloaded every day. So these are the main points that attracted us.
On the downside, of course, she can't physically pass on the books to me to read after she's finished. I need to invest another 100 quid for the basic Kindle for me, to do that. Then, she can, because the books are held on an email account and can be downloaded to any Kindle on the same account.
But there, the sharing has to end. You can't pass them on to mates or family, nor can someone pass their downloads to you. That will be the main disadvantage I think. However, so far the prices for the books have seemed quite reasonable so we will have to get used to paying for ALL the books we read, as opposed to borrowing and browsing in charity shops and hotel libraries!
(One other thing, don't waste money on a Kindle case for 30 quid - loads just as good for about a tenner on ebay etc...)