Well Thank you for all the replies & the discussion of PDF vs a raster image file.
From the sounds of it, a Monochrome TIFF raster file is a better bet than PNG but isn't a JPEG compressed more? So if one has an 8mg PDF converting over to a TIFF file vs JPEG file, ... well I think it would depend on the one doing the conversion, how well they know the software (Acrobat, Bluebeam, Acroplot Pro, etc), how well the software converts the file & the compression, etc.
I agree with the DWF(x) completely, I use to work with them all the time, back when the DWF viewer from Autodesk was 1.2 meg in size. You could copy the .exe file to a 3.5" floppy disk & send it with your drawings to a client. I was a big promoter of DWF's, but for some reason nobody else liked them so we quit using them.