They reckon a non IR rated pilot will loose control within 90 sec of going into IMC conditions.
I think that once airborne with everything up and running and a clear day ie not IMC you could fly it with PPL knowledge as the 9/11 hijackers proved, but they didn't need to learn how to land it!!
You could probably talk a PPL through an auto land set up with guidance on speeds and flap setting provided the A/P & A/T was left in, otherwise i think it would get away from a PPL because of the large pitch couple with under wing engines.
Even an IR rated pilot would do little better, because of the need to understand the programing of Flight Director systems.
If your interested in finding out have a word with one of the fixed base 737 outfits, i reckon an hour in the sim and you would be able to land it ok.
So its not a special skill set, its training