I'll be honest, it's been about 17 years, maybe 16 on the generous side, since I played FFVII, and I only played it once, so I honestly remember almost nothing about it!
So I am not the one to ask about comparisons, anyway.
Based on what I do remember, I absolutely love it!
The battle system is great! It's a lot of fun, and you can easily switch between characters. Also, you can switch back to classic turn-based, but I like the default system. It does kind of a bullet time thing when you're in the menu so it's not like you're trying to do things while the enemies are just whaling on you. If you've played FFXIII you'll be familiar with the Stagger system. If you do enough damage to enemies, they are staggered and take extra damage. Some enemies are weak to specific spells, some are weak to physical attacks, etc. I think that part is pretty standard. The combat still uses the ATB system, and you build it up faster with the character you're controlling. Tifa is a lot of fun to control, so I use her the most, but Cloud and Aerith and Barrett are fun in their own way as well. The hardest part about the combat is honestly deciding which materia to give to who. Early on, you don't have a lot of materia slots. But you can upgrade the weapons to add more as you get further in the game. The level up system for the weapons is also a bit like the Crystarium from FFXIII. There's rings of options and you get Action Points that you can use. Each weapon levels up at its own rate so you'll probably end up checking the weapon upgrade option often just to see if you accumulated enough AP to add another bonus to the weapon.
If you buy a physical copy of the game, it has a download disc that you put in first to make the process go faster. Once the download disc is done, you put the game disc in. I think it may have taken about an hour, maybe an hour and a half to do the whole process for me.
I thought I wouldn't be able to get used to the voice cast (they aren't the same voice actors as Advent Children or FFVII character appearances in Kingdom Hearts and World of Final Fantasy) but they are all pretty good.
Overall I'm very impressed with it and I'm kind of putting off finishing it because I know I'll just want the second part to come out already!
But I might also try to platinum it; haven't fully decided yet. One of the trophies is for beating it in Hard mode, and you can't use items in hard mode, so I'm debating whether I want to take on that challenge.