In fact, I stopped playing the demo to avoid any further spoilers. Watching Mads & Tara's relationship deteriorate, wondering how or even if they'll patch things. Then really crazy stuff starts happening. By that point I was hooked! and had to finish every route. Totally worth every penny.

Though I am kind of glad I did play the demo first, the intro really sets things up well. If possible, I'd suggest integrating the demo's intro to the start of the full game.