I have really enjoyed this show so far, and I really hope it gets several more seasons to finish its story. I think its unfair to expect it to be exactly like the original show (ie all the reviews that are directly comparing Piper to Mel or Maggie to Phoebe) because this is a reboot, not a remake.
The show takes a few episodes to find its footing, but it really gets better and better as the show progresses. It seems like they didn't expect to get a second season, thus making the first season seem packed full of plot but I didn't mind that.
As for the characters, I love harry so much (I personally think he's a better character than Leo, as long as we are comparing). He has more substance and character development. Then, as a scientist I enjoy Macy and her "magic is just science that hasn't been discovered yet" mentality. Mel starts out pretty preachy but mellows out throughout the show. So far I've only actually liked one of Mel's love interests (Jada). I feel like so far they've really only added Mels random girlfriends in as afterthoughts. Like Nico? She and Mel had zero chemistry and I was glad they broke up. I wish Mel's love life got the same treatment as, say, the romance between Maggie and Parker. I love Parker and I hope Maggie stops bein dumb and takes him back in season 3.
A lot of reviews here also complain about the sisters using 'dark magic', however the first season emphasizes that 'theres no such thing as magic that is inherently good or bad, it depends on the person using it'. I'm not sure what people are referring to that makes their magic wrong somehow. I do wish the show applied this concept to their approach to demons though, rather than always assuming all demons are evil all the time. However, I can see the development of the idea that demons could be good too, and hopefully they pursue this in later seasons.
Overall, I think this show was very entertaining so far, and it has the potential to be really great if given the time to grow. There are many great shows that took a few seasons to really catch their rhythm. The trend nowadays of cancelling shows after only two seasons is ridiculous; I sincerely hope this show doesn't fall victim to that.