There are electrical outlets for charging phones and laptops and the windows are big, allowing for full views of the speeding landscape. We were travelling in the evening, the view being the blurred lights of a seemingly endless city.
Passengers: Mostly local commuters, thankfully, as our group of nine travelling with Heartland Japan all had luggage. The overhead racks got full pretty quickly.
How full: The train was full when we left Hiroshima, but there were many stops with passengers getting off and on along the way. There was still plenty of room to relax, however.
Entertainment: Apart from the regular announcements (in Japanese and English) for impending stations, we had to make our own, talking about our trip, food, culture and the train. Somebody promised a pack of cards, but they had gone missing.
Service: These very fast trains are efficient at moving lots of people quickly between the huge cities along the Japanese east coast (and beyond). Although expensive, they are extremely popular: most people save a little money by taking their own food and drinks along for the ride, purchased at the vast array of shops and vending machines in all stations. There is, however, a service cart that makes regular trips up and down the train selling hot and cold drinks (beer included) and an assortment of food, some served hot.
Toilets: You'll find toilets at the ends of every other carriage. This is Japan, so of course they are clean and functional, but take a little getting used to. Even though these hi-tech trains are very smooth, they still bump and roll enough to make negotiating a urinal a little tricky: I supported myself by bracing my head against the wall at one point.
Station experience: I've always found train stations exciting and prefer them to airports. The big stations are allied to vast shopping complexes, which is great for stocking up on refreshments for the journey, but not so good if you get sucked into the whole shopping experience and don't keep an eye on the time. If you are in the mood for a shop, put an alarm on your phone or watch to give you a bit of notice of the train's impending departure. These trains run on time and they don't wait for anyone.
Final word: It's easy to see why these trains are so popular for both local commuters and international visitors. Comfortable and efficient, there's room to move about, even go for a walk, and the views would be fantastic during daylight hours. Plus, they stop almost where you want to go (centre of town, nearby suburb or even the middle of the countryside). A much more civilised experience, to my mind.