I didn't know anything about Higurashi before watching GOU, but I do see now why the series has so many loyal fans.
The series is set in the rural village of Hinamizawa in 1983, following a group of school children as their idyllic day-to-day lives slowly descend into madness. The show is divided into five arcs, each of which follow different turns in the events that lead up to the local village festival. For the first three arcs, the story follows the protagonist Keiichi as he becomes closer friends with either of the girls in his group of friends; the last two arcs are told from the perspective of one of the girls.
The high points of the series certainly are the lovable characters and the intricate storyline, which often gives rise to fantastic cliffhangers. This, unfortunately, also is the biggest downside in my opinion: act four ends with a magnificent cliffhanger that honestly is one of the best I've ever seen. However, act five does not resolve it; it's instead left to the sequel series to tell how the story concludes (and, if the ratings are any indication, it does an absolutely terrible job of it).
While the fifth arc is a terrific story in its own right, it does not work as a conclusion to the series. Similarly, the final episodes of arcs one to three often feature a scene where one of the characters tells the then-protagonist what else happened off screen; this honestly feels rushed and comes out of nowhere.
It feels to me as if it would've made more sense of combining GOU and its sequel, SETSU, into one (longer?) series. This way, I certainly don't plan to watch the sequel and am left disappointed. Oh, well.
Apart from that, the series does a genuinely good job. The animations are nice but not stellar, the (English) dub even works pretty well, and the series itself is highly entertaining.
There's certainly a content warning for gore, though. I don't really mind if anime turns violent, but the graphic disembowelling was perhaps a bit much.
