I don't have any experience to share, but those do look pretty nice. I wouldn't mind a silicone version as well. I wonder how the touch screen responds through the case and also through a screen protector.

You would give up quick keyboard accessibility though, and you would have to pop it out to put it in a car mount as well- Although the metal would prob kill your GPS signal so you would end up having to take your IT out of the case anyway.