Recently I had a chance to try out presets, introduced by Sleeklens (company that provides workflow for professional photographers).
I have never been a huge fan of presets but this time a gave it a chance and... it works out nicely. I didn't like the color exaggeration for some of brushes but most of them worked well with my pictures. I liked the "Brighten shadows" tool the best.
In short - easy for using, large collection, highly recommended for those who don't mind using presets in their photography and are too busy for editing pictures in more complex ways.