My biggest problem with the directory is simple. It doesn't work. I've tried copying from there and into a variety of themes - and most layouts seem to break. Stuff flows into sidebar, breaks main layout, has spacings totally different from that which is shown in the directory, etc.

I love the concept* but in practice it just doesn't work.

(* I'm actually a bit worried about the concept of this AND the whole "let everyone edit everything" notion of Gutenberg in general. I'm all for freedom - but as an agency trying to keep brand on track, prevent clients breaking All The Things, there is too much room for clients to mess stuff up right now in WordPress. Am hoping we see more control over the coming months!)