I just started using checkvist and I'm really enjoying the format. As a software engineer, a keyboard first approach is great. I dislike using my mouse.
Have you see http://www.moo.do/
? It's a new app in the "list to do app" space. Very similar to checkvist. They don't quite have the features but they are moving very quickly.
The feature I feel you could pull from them is the multi-pane approach. It's a great use of space on the screen. Basicly, you can add new panes of different list types on the screen.
After evaluating both, I did end up choosing checkvist due to a more mature feature set and the keyboard shortcuts but keep your eye on this company.