I am new to Omni, and I have d'loaded the demo apps to try them out and see which one fits me best, but I am wondering if Plan, Graffle and Outliner overlap features?

Do you find that you have migrated to using one over the other? Are there certain tasks that one excels at over another one? Do you see Plan (since it is new) replacing Graffle or Outliner ever? Or are all three complimentary (one giving its output to the next for further work)?

Sorry if this is obvious. I will try all three and answer my own question, but I'd appreciate your replies. You have undoubtedly tried these apps out and have your opinions.