I have been a big fan of Omni Outliner on the Mac for a long time.
Problem 1. When working on a project, I put links to web sites in my outline. That way I can find them quickly. Click on the link, and the page opens in the browser.
However, with the iOS versions the links do not work!! They do not even show the original text! If they did, I could copy the text and paste them into a Browser.
Really limits the usefulness of the iOS version.
Problem 2. The cloud sync / transfer of files does not work. Beta indeed!
DrScience about OmniOutliner 2