Quite very unique and usefull brush sets, the creator used to post them on deviantart but opened her own site and calls it "The fifth muse brush gallery".
I love Annika von Holdt's brushes. I think they are beautiful and can be very useful. I've definitely used them before. Her brushes are among my favorites.
I've seen that site before and had download many of her brushes. Honestly though, as much as I like her work, I, personally, haven't used the brushes, even though I thought I would.