The VN makers that I know of that have editors are very inflexible. The flexible engines don't have an editor. I know of one engine that comes with art but the artwork is user made and inconsistent in quality and style and the engine itself is pretty limited. The engine that's coming promises to have an editor, be somewhat flexible out of the box and a lot flexible if you code, and comes with a bunch of high quality matching artwork. Nothing is really unique by itself, but I think the combination is worth it. I mean, I love Ren'py, but it is not easy to make the menus look custom if code isn't your thing. Even just tweaking the colors for it can be a chore.
If it turns out to be another straightforward engine that you can only make one look for without knowing code then it won't be worth the cost, but so far it seems to have some unexpectedly high end features like Live2D support and most of all it has Archeia's approval. That's a big deal for me. I haven't seen it yet but I'm positive that it's going to be really great.