I have the Sierra, and unlike an earlier poster I find that I _can_ put it on my lap, it doesn't fold up at all. It's just not completely stiff. But I had no problems writing a long email in an airport recently (no tables anywhere, so I put the N800 on the next chair and kept the keyboard on my lap).

The keyboard is nice to type on. The only problem I have with it is that the screws (or rather where they're screwed in) don't seem to be high quality. The keyboard arrived with one broken, and a few days ago another fell out when I opened it. It wouldn't screw in again, so I'll have to apply locktite here and there.