The original was a trainwreck, so I have no intention of watching this one.
From what I remember, the original had a fantastic performance by Angelina Jolie, but a mess of a script and distracting CGI. The weirdest thing was how they tried to make Maleficent not a villain, and had to alter the plot of Sleeping Beauty in ways that didn't work. It started off by following some of the original plot beats from the Disney animated movie accurately, but then when it came to the third fairy-godmother giving her last gift, she gets interupted by the arrival of Maleficent, and then the movie completely forgets about it. It was an obvious setup that had an important purpose in the animated movie: because the third fairy-godmother uses her gift to transform the deadly spell that Maleficent casts on Aurora, into an eternal sleep. But the live action movie leaves that plot point hanging and then goes off to do its own thing. It ends up feeling like a cadaver of the original story.
There's a plot twist at the end that isn't actually a surprise, because it was copied from several other movies that came out just a year or two earlier, such as Snowwhite and the Huntsman in 2012, and Frozen in 2013.
And like I said, the CGI was so distracting. There are large action scenes where you are clearly watching a CGI Maleficent with Angelina's face awkwardly pasted on top of it. What was also confusing, is that Maleficent doesn't actually turn into a dragon in the movie. Yes, there is a dragon at the end, but she does not transform into it herself. I had to remind a friend of mine of that detail, because she misremembered it. It is such a bizarre and confusing change.
It is a shame that the script was so terrible, because Angelina really is perfect for the part. But no matter how hard you try, you can't make the character of Maleficent into anything but a villain without completely butchering the original fairytale.