TouchFire actually takes up much less space than a Bluetooth keyboard. The wall thickness of the silicone keys is half the thickness of a credit card, and it is flexible so it can fold with the iPad's cover.
And you can quickly retract it off the screen when you want to do non-typing tasks. There are magnets in all four corners which snap it into the retracted position. Take a look at the iPad 1 video on the Kickstarter site. That shows retraction in use...
Actually, TouchFire does hide itself when you don't need it. It quickly retracts when you want to use the entire screen, and you can easily pop it back up when you want to type again.
All use cases are equal, but some are more equal than others. Being able to touch-type fast without looking at the iPad's screen is a pretty big deal...
A key feature of TouchFire is that it can be easily retracted when the user wants to use the full screen. And it automatically aligns itself with magnets; it snaps into place on an iPad 2 (it also automatically aligns on an iPad 1 with the Apple cover).
By the way, I love TapTyping. There might be some new speed records coming your way soon from TouchFire-enabled iPads...
Actually, it is attached with the equivalent of a hinge. The user can quickly retract TouchFire while it is attached to the iPad, giving full access the entire screen. And they can quickly pop it back over the screen when they want to type again.
TouchFire creator here to clarify a few things. TouchFire does let you rest your fingers on the home row. That's one of its most important features. Also, you can quickly retract TouchFire out of the way, letting you use the entire screen (see the video for a demo).
TouchFire is a really new idea, that in many ways flies in the face of conventional wisdom. I've actually spent most of career doing software. When I first came up with the idea, I thought it was pretty crazy too, for many of the reasons people are trashing it here.
What's so non-intuitive is that TouchFire works. And it works really well. It lets you touch-type on an iPad, while at the same time effectively disappearing into the iPad's cover when you don't need it.
We have found that actually using it is a very different experience than watching a video of it. Would people be interested in having a meet-up to try it out in person? We could do one in Seattle and one in the Bay area if there is interest...
No need to lift and put back every 2 minutes! TouchFire remains attached but can fold out of the way very quickly when you want to use the whole screen, and unfolds back when you want to use it again. See the Kickstarter video for a demo of this, about 1/3 of the way through...