Aside from some stuff, not a very good adaptation and the 2017 one was a lot better
Hell, even with the bad CGI and jumpscares, the 2017 was way better. Even if they updated the setting from the 50s to the 80s, it didn't ruin anything. The 1990 miniseries has not only aged poorly, but the acting wasn't very good. Not saying the acting is fantastic in the 2017 adaptation, but it was a hell of lot better then the 90s miniseries. The Losers Club in the 2017 one were a lot better and more relatable than their miniseries counterpart. The ones in the miniseries were just comparable to any afterschool special from the 70s. Also, with it being set in 1960, the only thing missing from these kids would be for them to say "golly" or "swell", like it was a goddamn episode of Leave It To Beaver.
People constantly say the 90s Goosebumps series has aged poorly and has poor acting, well guess what; the IT miniseries is no different. At least the child actors are decent and Tim Curry was by far the better Pennywise of the two adaptations, but in all honestly, it's not a good adaptation and only blind nostalgia is why it still gets loved. It's a shame the 2017 gets criticized. Aside from the bad CGI and jumpscares, it was actually good. They didn't ruin anything. Yes, the bullies were aged up to teenagers and it makes sense. In the novel and miniseries, they were the same age as the losers. Them being older makes it more believable when they pick on the losers. Yes, I'm aware bullies can still pick on kids their exact age but older bullies tormenting younger kids is more terrifying. Also, them not being greasers wouldn't work for the updated 80s setting.
Two scenes I actually like in the miniseries and have actually aged well; The scene where Georgie meets Pennywise and gets eaten and the follow-up scene where the older brother Bill goes into his younger brother's room and feels remorse for his death and the photo album comes to life and leaks blood.
The rest of the miniseries after that goes downhill. The scene where Ben sees Pennywise in the barrens disguised as his dead father is not scary. The scene where Eddie sees Pennywise in the school's gym showers is not even trying to be scary at all. The scene where Richie sees Pennywise in the school's basement in the form of a warewolf was just cringy. The second part is just awful and filled with bad soap opera levels of acting. The adult actors weren't even trying and they got some really good ones like John-boy from The Waltons and John Ritter and their talent is wasted. Even the actress (who just died recently) who played Norma Bates from Psycho IV (also 1990) was wasted as Bill's Wife, Audria only gets a few lines of dailogue.
Even if the 2017 one wasn't all that scary, it was still very entertaining and they don't shove the 80s down your throat like Stranger Things does. Also, why do people blame the 2017 one for being a Stranger Things knockoff? The remake was planned way back in 2010 and was originally going to take place in 1985, which is the same exact year the second half of the novel took place. ST didn't exist yet. Also, the changes in the 2017 were better. Bev is actually a ginger whereas in the miniseries she had brown hair, making the whole poem from Ben make no damn sense. Like what's the point of her hair being "January embers" if her damn hair isn't even red?