Good for you on the publishing of the book! I'm gonna sound all old man here, but I still like having a physical book for pleasure reading. The older I get, the more I want to disconnect from screens on the weekends.
I agree 100% on physical books for pleasure reading.
I would also have real hard time with e-books for technical classes especially
engineering.
You're constantly going back and forth between chapters and tables.
Could not imagine being able to do that efficiently with an e-book.
Recently I tried to design a pedestrian bridge using the digital Steel Construction Manual.
Much more cumbersome to use then the printed version.
I've posted that I do some lecturing at F.D.U.
So far the students in the Civil Engineering and Land Surveying classes I've lectured all use hard copies of the texts.
My life loves her Kindle,but all of her cook books are hard copies.