In my case, the trip was supposed to be relaxing as well as cultural and included staying in Osaka and day trips to Kyoto, Nara, and time at Expo. To accomplish this for a family of 4 at the last minute, trying to understand train schedules and carting luggage spelled STRESS and waste of money and little enjoyment time. I know I made the right decision.
I am also very happy that Hertz is being very clear about the need of the IDL.**