Perhaps I'm in the minority, but I find PDF versions of documentation absolutely essential. I like having a printed manual, but there are so many advantages to a PDF version that I feel hamstrung if restricted to printed paper.
For me, the two greatest advantages of a PDF document are (a) if created properly, it's searchable (so I don't have to manually hunt for topic discussions), and (b) when I'm actually using a piece of software, it's usually more convenient to have the documentation displayed on screen (easier to bounce back & forth between the software & the online documentation than to bounce back & forth between the software & a physical user manual in my lap).
Moreover, the DP 5 manual is so large, it's prohibitively cumbersome to try to reference the manual while I'm at the computer trying to use Digital Performer.
So, why am I posting this? Because MOTU currently does not provide PDF versions of their user manuals. But if DP users would just take a few minutes to contact MOTU & request PDF versions of user manuals, I suspect MOTU would promptly comply. Given that all current user manuals almost certainly exist as computer files, generating PDF versions is a trivial task. Digidesign, Roland, & other music product developers provide PDF versions of their full library of user manuals. It seems reasonable to ask MOTU to follow suit.