Ok, I finally took a cab after midnight from the airport to near Shibuya station. 22 km ride and it cost 8650 yen. The station is 2 km closer by car so it probably would be just below 8000 yen to Shibuya Excel. The toll was 560 yen (?). It appeared above the running fare on the meter display as he went through the ETC gate. So the fixed fare of 8000 yen (plus toll) is not worthwhile to this part of Shibuya.

The driver was great, going 130 km/h at times and completing the journey in maybe 15 min. Didn't use GPS either, although I had to alert him to the final turn.

I came off a domestic flight at T1. The bus timetable for the 00:30 departure shows >> for the domestic terminal stops, which I assume means that it doesn't stop there. Otherwise I could have caught the 00:30 bus. Pretty lousy scheduling when they know that there are flights coming in just before 00:30.

Most of the people were hurrying away from the cabs. I saw a few private cars waiting in that area curbside, but the ratio of people to cars made me wonder where these people were heading.