> The good news is that if you are a control freak (and what designer isn't, another reason for the lock down) then you can simply design for PDF. Which, if you require actual layout control, and not just typographical control, is a world class standard (one with LOTS of design options.)
Yes. But remember: PDF is still evil. Go for PS instead.
From a user's point of view, PDF is a good experience, at least for highly formatted documents. By this I mean documents for which the specific layout, placement, and aspect ratio is an integral part of the authorship. A comic book/comic strip or a diagram meant to be viewed a certain way are examples of this. Lots of the technical books I have are designed such that to change their visual presentation would require changing the actual content. Like it or not, there's tons of pre-existing content designed for a specific presentation, and PDF (or postscript) are a good choice for that.
The biggest problem with PDF is that it usually requires a specific page orientation and aspect ratio, if not a specific page size. This is okay if you have a large enough display and can resize your viewer window to suit, but it's a bit more of a problem on smaller displays, or irregular shaped or resolved displays. For those, a liquid layout and typographic styling, something like HTML or ePub makes much more sense.
Yes, it does. My comment was meant comparing PDF and PS purely as languages. PDF is basically a premature optimization of PS: They replaced the plain text PS commands with binary commands in PDF. That makes PDF on average smaller than PS.
But--similar to WiFi relying on special purpose encryption instead of using standard algorithms--PDF is bigger than compressed PS (e.g. .ps.gz).
Yes. But remember: PDF is still evil. Go for PS instead.