I've read a few on my laptop in the past (40+ I guess) but the thing wasn't comfy enough; I read _a lot_ of paperbooks.
Now I've had a CyBook for a fortnight & I already read 12 e-books (Peter Robinson, William Gibson & lots of kinky XIXth century French detective novels... nobody's perfect).
I'll probably go on buying (paper) books, but I'll never ever again haul them around the world with me when I travel, + I intend to amass all the reference I need in my E-book reader.
Next, I want to read my morning papers with it too.