I've used this about 10 times now and at least half of the time it ends up being faster to use the normal queue. The only reason I don't just go back to using my ABTC card is that I don't want to waste passport pages on the silly stickers they use in the normal queue,
Half the time the Windows-based kiosk software crashes and they have to restart it, or the single machine they have dedicated to non-Japanese is not working for some reason.
Every time I complain and ask why they only have one machine that TTP users can use (out of the 4 they usually have). The answer is usually along the lines of "ohhh.... TTP sukunai ne" (e.g. there's really nobody that uses this). I've even filled out those forms at the Suggestion Box they have nearby the immigration area at NRT. Of course, nothing...
Tax free shopping... that's a joy. It takes a couple of phone calls usually at BIC camera for them to figure it out, especially if you don't bring along your passport. I've always eventually had success with it though every time.
One positive: the card works great for ID purposes. Nightclubs, etc.