Hog Bay Notebook
Being a huge fan of outliners, I’ve pretty much tried them all. OmniOutliner is about the best of them, but is a little too twitchy for my taste. If you like outliners but wish they would manage larger amounts of text or include a better search engine or basically just feel better, look no further than Hog Bay Notebook
Here’s a screenshot of a (seriously pruned) version of the notebook I use for managing my GTD tasks…
It’s light, fast, and feels exactly like an app such as this should. Better text handling than OmniOutliner and better outlining than DevonTHINK. I’m diggin' it.