@octoambush I'd say the manga for Higurashi is a pretty good approximation, all told. There are bits and pieces here and there that the VN does better (particularly toward the beginning, which is faster paced in adaptation than the answer arcs) but I'd be way more confident saying it and the VN are alike than the anime.

For Umineko, the VN is required reading. Though the Episode 7 and 8 manga are also huge recommends once you finish it, since they actually go out of their way to add stuff not in the VN which Ryukishi oversaw.