I really think they're very different applications. I think in nodes and much prefer Nuke, but AE being timeline based gives it very different strengths. Nuke also doesn't manage video and synced audio and is better optimized around frame sequences.

In school I'd often see people edit their projects in AE (because they were too lazy to learn Premere or another proper editor). It's not a great idea to use AE for editing, but its possible. If you tried to do that in Nuke you'd throw your computer out the window.