Better than FF7 remake in every aspect, Rebirth expand on the PS1 original scene with really cool ideas and make some character shine a lot more than before (Yuffie and Vincent actually present in the story instead of just side content or lore is a great exemple, barret or cait sith are also really good).
Also come with a lot of quality content which may feel boring at first with the ubisoft tower and open world but is still fun to do and offer some great moment.
The "new part" of the story tries to build upon the remake weird premise and is ok, even if it tries to use way too much things from CD2 and 3 making the ending feel maybe too easy.
The story really shine when it take the original and add some cool stuff on it (Dyne,gold saucer etc..)
Overall still a really great game and a really good Final Fantasy that shine more than for just being a remake, while staying closer to the original than the first part.
Part 3 will need to confirm that all those story changes are worth it.