I don't have one yet but the readability of the e-reader is much easier than the laptop, carrying a laptop to the doctor's office is a bit of an inconvenience besides the weight, you can read an e-reader in bright daylight, you don't have to carry around the weight of your books in your rig, and the battery life of the e-reader is much, much longer.
What I don't like about the e-reader is the price of e-books is almost the same as a hardback edition, though an e-reader can have 3500 books on it. I also like the feel of a book in my hand but that might be habit. There are also 2 million books that are free(out of copyright).
I haven't heard of one person who dislikes the e-reader, most rave about it. Amazon is selling more Kindle books that paper copies, that shows me the world is changing and we should probably change with it. Kind of like the cell phone, initially we resisted, now we don't know how we lived without it. Same with the computer, cars etc.
The e-reader also can do more than books. I know the Kindle can do pdf's and plan to download my rv pdf's to it and get rid of the notebook in the truck.