Number 6 on my list is performance.
When we first started Tabris.js we used Rhino, and our animation demos ran at about 10-15 FPS. With V8 now powering Tabris.js on Android, we can run smooth animations at 60 FPS.
To try this yourself, simply install Tabris.js Developer Apps and run the Canvas or Animation demos. To develop and deploy your own apps, visit https://tabris.com. For more information and to hear about the Top 5 Tabris.js features, follow us on Twitter.