If you are relying on them guaranteed some dude sick of being turned down by his anime girlfriend will "enter the operational area" and make you wait hours. My Legacy is overkill but that's no need to commit acts of self mutilation and buy a K! 
[/quote]Used them everyday for more than 20 years all over Kanto from local to the major lines and in that time I could count on my hands the number of stoppages during my time there. Typhoons, mechanical issues
and of course you have your jumpers on the Keihin Tohoku, Yamanote, Chuo and in particular the Sobu line. Things may have changed nowadays though...
A lot of my friends had cars that they rarely drove, from large family vans/sedans to K cars and most of them regretted buying them and ended up selling or giving away their vehicles. Most of them now share a community car in their apartment block, the more popular ones which I've been told that they drive nowadays are the Honda Fit, Toyota Aqua, Toyota Corolla and Toyota Prius.
How could anyone say the trains in Japan aren't but 99.9% perfect. On time all the time clean safe go anywhere fast and if you want to get there faster get a faster train . We went to Koyoto for dinner from Shinagawa 530km 2 hours 20 minutes had a few beers on the way .Fantastic day out. I travel into Tokyo twice a week and it would be totally impossible to do the trip any other way other than train.