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.

you're not alone.
traditionally, MOTU used the lack of a PDF as a sort of poor man's copy protection. but those days are gone, and we've got to authorize each install. i second your motion. i'll drop 'em a line.