Knuth's books aren't only timeless, but they are beautifully typeset, printed, and bound. I don't feel like I'm missing anything special along these lines when reading an ebook novel, but I have yet to see the experience of reading a really nicely produced book on a digital reader.
Even if you had the TeX PDF output to read, it's not quite the same. Now maybe younger folks today are so used to reading things digitally that they won't care or notice the difference; I'm not sure.
Knuth wrote TeX in the first place in the 1970s because he missed the experience of reading a really nicely produced book on a digital phototypesetter. History may not repeat itself, but it does seem to have an echo sometimes.
I was disappointed in the binding of Volume 4A. It's the cheap hard-to-hold-open kind most publishers seem to have switched to around 2000. They didn't even give the pages wider inner margins to compensate.
I decided I'd mention it if I had occasion to write him about anything else. Surely he's seen it, and I imagine it's just hard for a book to avoid this fate now. It's a pity, though -- I'd rather have an electronic copy (assuming no DRM) than what his publisher put out.
Even if you had the TeX PDF output to read, it's not quite the same. Now maybe younger folks today are so used to reading things digitally that they won't care or notice the difference; I'm not sure.