Well, I've done my share. I own a few of the Kenzer/Necro modules, but it's really only on the reputation of Necromancer games and it's authors. As far as the Kenzer/Necro books go, I have:
A Family Affair - print
Six Spheres of Zailhhess - PDF
Doom of Listenshire - PDF
Diamond Fortress - PDF
Mother of All Treasure Tables - PDF
Shades of Gray - PDF
Tower of Jhedopar - PDF
For a while there, I thought that Mother of all Encounter Tables and Crystal Skull (cool module) were Kenzer, but I think these were some of the last Troll Lord publications. I have both of those in print.
Oh -- and of course many of the Necro classics (new and old) too.
As you can see, PDF is my preferred adventure product medium, but in many cases I will own the print and the PDF (like RARe, Ptolus, Wilderlands, etc), all legit and all paid by me.
This whole double buying thing is a drag, but I find that the print is best to curl up, take notes in, and read on the sofa... and the PDF for in game play -- I also cut/paste stuff for my players.
I wish that print product purchasers could get a discount on PDF versions.