Finally just finished my second run in 999. I have to go spoilerville:
DAMN. THAT was the safe ending?! Seriously? That was freaking epic, and felt like it should have been the true ending. Ace gone crazy, the incinerator scene, then poor June(Akane) disappearing right at the end. The credits even rolled like I was all done. This all took a couple hours. I have a very hard time believing any other ending will be better than this one. I'm already looking forward to playing Zero's Escape. Crazy stuff.
I really don't feel up to a third playthrough after all that. I'll do it, if you guys insist, but it feels done to me.