I want to package it up so it's super simple for a regular user to install and run it. No installing of runtimes. Just download an app, double-click, and start editing, and configuring via web forms. It can't run in the browser, because it has to access the local file system.
If either of them had a simple Hello World app that I could run and start working with right away, without having to wade through docs by trial and error, I probably would go with that one first.
I'm looking for advice from the people who read my blog who have used one or both of these toolkits. The result will be a new capability for the open web. So you're helping a good cause.