I've been through Narita more times than I can count it seems, but
never out of the airport. I may end up with a 9 hour layover at NRT.
Is that enough time to actually *do* anything in Tokyo - figuring the
time it takes to get to/from the airport, checkin/immigration etc ?

I can avoid it, but usually do the 6 or 7am flight from BKK, which
doesn't actually help me much since that requires leaving for the
airport at 3/4am and not really sleeping anyway. This 9 hr layover
flight would have me leaving just before midnight instead, arriving
into NRT in the am. I'd only do it if it offers me the chance to do
something in Tokyo.

Thanks
X.