Another thing that's better about reading on iPad versus a laptop or desktop LCD screen is that you can hold it almost any angle. To me, that's the best advantage. I read and write a lot on my iPad, and being able to sit with it at a more comfortable angle is a huge advantage to me. It definitely feels better on my eyes after looking at a desktop monitor for hours. That'd be subjective, though, but my experience is that the iPad feels easier on my eyes.

That said, I'm not sure if it's better on your neck versus a standard laptop in your lap. My neck hurts if I'm using a netbook on my lap too long, so I'm always using it at a desk or table. It never feels that bad typing in my lap on iPad, though.