I use the app, and have skipped doing the paper form all together by now. The Haneda setup is better than Narita, as you can use the kiosk while waiting for luggage. Narita you can only get to the kiosk after getting your luggage. But apart from the initial teething problems, which was basically too few kiosks, and people not being used to the flow, it has become very smooth to use.

I wonder though, does people ever get selected for check of their baggage. There used to be a sure fire way to ensure you'd be stopped for more questioning, I'll have to try that next time I come back home. It will also tell me if there is a visual judgement aspect