If anyone's spent some time in Japan, they probably rode the Saikyo line at least once, between Shin-Kiba and Kawagoe, passing through Shibuya, Shinjuku, Ikebukuro, Akabane, and Omiya.
This train is an absolute mess. Cramped, dirty, rickety, noisey.....but now, they have a brand new EMU which will be phased in the next few years, the JR E233-7000 series EMU. This EMU is currently employed on the Chuo line, the Keihin-Tohoku line, and the Keiyo Lines. Newer models (the Keiyo, the new Saikyo ones, and the upcoming Yokohama line series) are built by a newly formed JR East R&D team in Kawasaki and are built on newer standards- LEDs, LCD information monitors on board, different materials for construction so the cabin is quieter....
I, by pure chance, had the honor to ride on board the new Saikyo EMU yesterday. It was amazing the difference a new EMU makes.
Some photos below:
E233-7001 (Set number 1) 平成25年 Year Heisei 25 (2013)
"E233系デビュー" "E233 Series Debut"
(photos suck cuz they were taken from my iPhone.)