Hard copy vs. electronic copy

Disadvantages of books:

1. Take up space.
2. Hard to search effectively and to copy selected matter from.
3. Almost always cost something to obtain, whereas electronic copy is sometimes given away or accessible at no charge through institutional databases, etc.

Advantages of books:

1. Long lasting.
2. Easier to bookmark for the very long term. (Finding an old bookmark in a book is often an unexpected gift.)
3. Three-dimensional material form aids kinesthetic memory.

Upshot: Even when I have only the PDF or HTML copy of a book, I often print a chapter or section to read from, mark up, or tote around to read outside.