Since development was halted on the Revit PDF driver, print quality using it has degraded with each release as others have noted. We've had lots of trouble getting the high quality linework we want.
Unfortunately Revit doesn't play nice with Acrobat and won't batch plot individual files with automatic naming.
However I've finally worked up a solution which is giving me excellent control of file size and plot quality.
I've set up Revit to print to a postscript printer - (I'm using a HP755 CM/PS driver because I'm familiar with it and it has the sheet sizes I want built in. However the generic Adobe driver and a PPD file free from Adobe's web site will do just fine too.)
I now just plot to file using this setup and postscript files are created in a plot directory. They do end up with the *.prn extension rather than a *.ps or *.eps extension, but Acrobat doesn't care.
I've got Adobe Distiller set up to watch that directory and automatically generate the PDF's. Works great and I've got the PDF settings refined for a sharper print than can be had from the Revit print driver.
The nice thing about this is that printing postscript is fast. And I can set up distiller on a separate system watching a network drive. So one system can generate PDF's for everyone. Glad to post my setup if interested.
(For presentation work you can't beat Revit->PostScript->PDF->CorelDraw....)