I really like to have both. For quick reference, electronic is best - so much easier to search! For more careful reading, printed.

Use case 1: my screen is only so big, so when I do intense Maple stuff, I sometimes have several manuals open at critical pages on my desk, while I work on my computer. [Requires printed]

Use case 2: searching for a concept and its uses in Maple. Then full-text-search is the only way to go (otherwise the index to all the books would be 50 pages long!). [Requires searchable electronic version]

Use case 3: I am using a Maple command with a complicated calling sequence, and it is hard to get it right. I zip to a good example of use of that command, and then want to cut-and-paste that into my Maple session. [Requires version which allows cut-n-paste]

Note that Mathematica allows me to do all 3 of these very easily. Drawback: that doesn't help Maple users much!

I would pass on distributing printed manuals with the product, even though I think the Maple introductory and programming guides are very nice. I ordered my original (black) version of the Maple V programming guide because I wanted a book, but now I have many copies of this book from different versions of Maple. They are almost all the same. I think you should distribute the current version of the manuals electronically with the product and sell printed copies inexpensively for people who want to have them.

Generally, I prefer printed manuals. Recently, I bought a digital camera of Sony where the complete manual exists only on the CD. Shall I take a computer with me during vacation? As compensation a got abbreviated versions of the manual at six different languages.

For computer software, however, an online version of the manual is generally OK for me. Manuals of thousands of pages are rather unexpedient. Only for very difficult matters I prefer to print some pages, make notes on them, and throw them away again when the problem has been solved.