If we get Midgar exactly as we know it in the original it's a missed opportunity. No question about it.
People bringing up how the original FFVII was mostly linear are forgetting that a) the game offered you the promise of exploration and illusion of freedom 7 hours in (as you left Midgar) and b) opened up drastically as you kept playing and c) was diverse as hell and d) was not a whole game dedicated to one location.
We're two months away from launch. We have yet to see one brand new area that was not in the original Midgar. It's already tiring from press material. For me, the game would probably still be really good if it's a fun romp through Midgar but with higher production values, but if they fail to take the main selling point for part one of a multi-game remake and the most interesting part of this game, then of course I'll be disappointed.
Also, I think that spoiler of the game length is BS. I think the game will be 20-25 hours. I'm mainly talking about content here.