Good points. The price point on those things is a bit hard to bear, but I don't think the idea of a smart-phone approach is likely to fly with governing bodies. The whole Monroi value proposition is wrapped up in the fact that the device features are dedicated (no analysis) and its proprietary wireless networking is more secure than that provided on other commercial wifi devices.
I'm not sure I'd be comfortable with my opponent using their iPhone.. My iPhone has about eight different chess AIs on it (apps installed locally), so Airplane Mode isn't a guarantee against naughtiness if someone has to go get a drink or use the washroom.

I wish Monroi would make an iPhone app. I can’t imagine it would be very hard. The UI would look nicer, and I’m sure it could be priced well enough to make profit on just the app and not the hardware. Anybody else think $350 for a product that does nothing but chess notation is a bit ridiculous?
Bearing in mind that there could be potential issues with iPhone/iPod apps and cheating, would you feel comfortable allowing your opponent to use an app on their iPhone/iPod? If so, what do you think the conditions of use should be (like not being allowed to remove the device from the table, must be run in airplane mode, etc)?