Illustrations are easily readable on the desktop nook application... ( I am using a 21.4 inch screen though ). My favorite thing about e-books..
1. They never get lost, damaged, worn out, or other losses.
2. Accessible in your library, anywhere in the world.
3. Search, using the speed of a computer for anything you have bookmarked, highlighted, annotated. Even search for phases, and topics you have not bookmarked, highlighted, and annotated.
When you are vacationing at the beach, and enjoying an ice cold Pina Colada, and are reading your favorite author... than a nice paperback is probably the way to go..... :-)
For a reference guide to your audio software.. the e-book benefits are hard to beat imo...