reliable editting of any PDF file
I'm struggling to find software to edit a PDF file. Firstly, I'm wary of
using a graphics editor to do the job and pdfedit  seems to reject
many of the PDF files I've just tried because they are "linearised"
according to the bug report 
So what joy have others had, or is this the Holy Grail ?
 ref to something that may or may not be obtainable but that many
people spend their entire lives searching for...