@aeonsovarius That's debatable. I like both cards, against dredge I don't like mulliganing to leylines where you can draw rav naturally. That makes for very weird games IMO as we can mulligan to few cards and then opp has some nature's claim and we have nothing. With rav trap they can therapy us too, but having the possibility of keeping a fast hand that can eventually draw into it seems like a better plan than mulligan to few cards.
Against the mirror leyline is better. But as I have had very positive results in the mirror and ok/bad results against dredge, I rather prioritize where I have room to improve.
Dark confidant can still be a thing, I haven't picked up the dark version because of the meta, but if we go down in combo that may be a possibility. It's a good version, but in this meta I prefer bug.
I don't think it's good to play chalice in the bug or dark version, maybe it's possible in those with lavinia but I don't have experience with that version to back me up.