ADV here is obviously the more prominent format, seeing that it allow the player to see the visual in which it's obviously the main selling point of the VN (Duh), so I never consider it as the way to allow faster narrative. Anyway, obviously ADV here would allow the people to enjoy the visual, so the drawings should be good if one want to use ADV. Of course seeing that nukige here is specialized in the visual excitement, almost if not all nukige would use ADV, although maybe one can use NVL format if they want to describe on what's going inside the people mind when they have sex. By the way I don't know which nukige that had NVL format here, so I may be wrong on this.
NVL will obstruct the visual, so obviously the art is put in the second after the narrative, with the main example is When They Cry in which it seems Ryukishi realized that as well if Rose Guns Days is any indication (He decided to use ADV there and he decided to hire several other artists with better drawing to drew several characters). That said, just because the format is NVL didn't mean that it can't have good visual, as Mahoyo (And obviously Fate) shown us, although evidently Nasu here put more focus on the narrative if his 400 pages of proto-Mahoyo here is any indication.
Well if I want to summarize it, it's kind of funny that ADV and NVL here is basically put the emphasize on the two words of 'Visual Novel' itself, with ADV put more focus on the 'Visual' part and NVL put more focus on the 'Novel' part. Whichever is the best, well it's up to each person, although looking from how ~19,000 VNs are using VNDB easy to say people prefer to put the focus on the visual (Which to be fair is easier to promote compared to the narration).