As someone who has been invested in Versus XIII/XV for a ridiculously long time, going through the demo was a pleasure. The music, the art direction, the premise of being in one of young Noctis' dreams, being lead around by Carbuncle. . .as limited and rough around the edges as this thing was, I was charmed the entire time.
It feels like I barely explored the gameplay, but I liked the changes from pre-patch Duscae (never checked out the update). I've learned to appreciate the level of automation in XV, and how it can lend itself to a FF-esque approach to action combat, but manual weapon switching makes it much more engaging.
I've enjoyed checking out some of the videos posted in this thread. It seems they've dramatically improved aerial combat, and it's great to see the warp mechanic looking cool and useful. I really hope the actual game teaches you the mechanics in a smart way. It needs to minimize the "this feels weird" phase, and get people to the "oh, this is interesting" phase much faster.
Overall, I'm feeling positive. There's room for refinement across the board, but the demo hinted at a game that has the potential to be great. At this point, my biggest worry is probably quest design. XV is releasing in around 6 months, and I still haven't seen any evidence that traversing the world will be interesting from a quest design perspective.