I had the entire BSC collection when I was a kid. I loved that they made this a Netflix show. Probably, the only thing I feel a bit iffy about is how they seemed to turn Karen into a snob. She's nothing like that, she's a very affectionate kid and is quite the opposite of a snob. I also don't appreciate how they seemed to turn Mallory into some kind of an immature dork. Enlighten me if they did change Mallory's family, but she's supposed to be the oldest of 8 siblings, and because of this, she's had plenty of experience taking care of kids. She's level-headed, mature for her age, and she's aspiring to be an author. Having her misspell 'diabetes' is very far off. I probably would've believed it if Claudia spelled 'diabetes' incorrectly.
Other than that, I think the rest of the characters are on point. That's just my two cents. I don't know... Maybe I'm just too hung up on the original characters, and it would've been great to see them in this modern day BSC setting, but still with the same personalities.