[panic]

A list of text links would be faster and more effective.

What makes you say that? The card interface gives a sense of context--you can still see the stuff behind it. You can pull on the entire card to navigate instead of hitting a small text target. I haven't used the UI, but it looks like it works pretty well.

[byron_fast]

To access a previous card, you could have a small target for each. The front one can always have a large target.

The card metaphor has no value. No extra information is communicated, and yet it is expensive to program and display.

UIs always look like they work well when demoed by the creator. Show me a usability test with this, and then you'll see the reality.