Connecting Tokyo and Osaka (500 km or 320miles) in about 2 and half hours, Shinkansen is a very reliable and fast and comfortable transpiration even when you compare it to the airlines. Jets fly from Tokyo to Osaka in about 50 minutes, but you need to take train, bus or taxi to get to the downtown area whereas Shinkansen gets you to the middle of the city. That is all good.
But there is one drawback I have to mention. Because Shinkansen has no competitor, the price is fixed and it is rather high. Unless you buy airline ticket at the last minute, airlines offer cheaper transportation between Tokyo and Osaka.
One more thing. Shinkansen have not accident since it started operation back in 1964. That is over 53 years without an accident.