I haven't played the demo and don't really intend to (my plan is to wait for the game to release and drop in price to $20 before picking it up), and I don't really have much hype for this game. The Final Fantasy VII remake does not seem like a game that's made for me, as I'm not impressed by the gameplay changes I've heard (the FFIV-IX ATB is my favourite Final Fantasy battle system ever, so the semi-real time version here looks like a major downgrade to me). My biggest concern is with how much the story is going to be padded out, as the original game takes me about 23-25 hours to go through and its narrative is not really that long; personally, I think the story's pace is going to get killed by the multi-part remake's numerous additions. As it is, the Midgar section of the original Final Fantasy VII takes me 4-5 hours to finish, and I'm baffled by how that section is supposed to be a 25+ hour game in the first installment of the remake.
On the positive side, it's going to be hard for this game to disappoint me, as my expectations are extremely low. Of course, Final Fantasy XV managed to be so much worse than my incredibly low expectations for it, so I don't have much confidence in Square, currently.
As for the refrain that "the original game will still be there": yeah, I know, but I view the remake as pointless if it can't be better, and I'll criticize it if I think it's worse, especially if all the releases are filled with bloat to extend this project to milk the game to a ridiculous and obvious extent.