To me it's the process of any artist. I think it's fascinating to know but whatever Gaga feels comfortably releasing and feels as though fits with the ARTPOP album, then that's what I would want to see.
Gaga played Princess Die at the Born This Way Ball, Partynauseous was played at the Artrave, Ratchet (instrumental) is on DJWS's EP and there's a clip of Gaga rapping a verse of it online, and there's a verse of Red Flames online, I don't think the other songs officially leaked other than Brooklyn Nights.
"Temple" and "Sire" were the ones I loved the most. I kinda wish GaGa and Azealia Banks could've collaborated because I'am now an Azealia Banks fan and can totally see why GaGa was set to collab with her.