Wow, times have certainly changed. I remember traveling from Tokyo Station to Hakata on the same Hikari (no transfers) in 2000. It took us about 5.5 hours.

While we did have a lot of luggage, the space between rows of seats (in the Green Car) was large enough to accommodate our suitcases which made excellent leg rests. Stocked up on Eki Bento at Tokyo station - no time to get out and shop during the 3 minute stops at stations along the way.