i THINK IT'S AN AGE THING..
I have an older laptop in the garage, and being able to turn pages with my greasy gloves on.. or in the winter, with my laytex+ mechanics gloves on.. and if I need even more info. hop onto the web.. and ask questions in a forum like here.. works better..
now I love to sit and read a book(paper) but when out in the shop/garage, books pages get dirty, and then sticktogether.. etc etc,
ideally, I'd like both.
most of todays books use junk for stock.. nothing like the old motor manuals that was heavy glazed stock..
the books cost would be a hard sell with quality stock used..
anyone thats been in the field for the last 15 years, uses computers in the shop/garage..
don't see why you couldn't offer whatever in print and digital.. as your book will be formed in the digital world.. so a digital hard copy(cd/dvd) wouldn't be hard to produce, cost wise.. print on good stock will be costly..
yes a digital copy can be copied,, but today I can scan a book into digital pages if I wanted to , in a few hours..
today when I travel.. it's the laptop and/or the wifes kindle.. as air travel and every bags is becoming costly to bring with you.. on a plane trip that may take most of a day with layovers,connections, a few books on a digital reader is easier than a 8.5x12" books..
thats my take..