I haven't pre-ordered yet; still on the fence about buying FF XVI full price. People are going crazy about the demo and prematurely calling it GOTY.
I found the demo very interesting, not necessarily good. The story and voice acting is very good. Cinematics are not the most important part of a videogame, not even when it's FF. If the gameplay part of a game brings me no joy then it's not a great game.
The action gameplay can be hard to follow due to the close camera, flashy effects and the need to track cooldown timers. There's a rush to target move but only in Ifrit mode, so you might have to press the toggle button twice to cycle back into Ifrit before you can press the gap closer. There's a block in Titan mode. You have to keep glancing at the HUD. This system is clunky to me. You can equip assist rings that do the moves for you, making it stay unfun but for a different reason.
They brought in a Devil May Cry guy. I've always preferred Ninja Gaiden. To this day I still hold up NG II as the best example of action gameplay. I don't remember ever meeting someone who agrees with me but the rest of the world is wrong, everyone is a moron and that's why we have so many shitty games.
NG II has a moves list like a fighting game and you just dial up combos; has no cooldown timers; has a higher camera to show enemies around you; doesn't have flashy attack effects that obscure parry windows; lets you jump and run up things during its kinetic battles for you to find the best positioning; is very fast. Then Team Ninja botched NG3 and switched to slow Souls clone games instead...
TL;DR Square still haven't made one great action game and I wish they stuck to the ATB system they had on SNES and PS1. It's like turn-based but time advances and each character can move when their bar is filled. They were better at strategic command-based game. Yoshida has great respect for that era but he still made something completely different.