On the Windsor to Waterloo line, I saw so many different types of rolling stock: a 707, a 458/5 and a 455. Why can’t all of the trains be 707’s on the Windsor line, because the 707's have plug sockets and the modern information screens.
Lots of the stock interwork and run different routes at peak time,so it would be extremely difficult for all Windsor services to be 707s. However, from next year the new class 701s will take over from all the rolling stock listed above on the Windsor line; and these are expected to be similar to the class 707s.
You mean ALL the trains will have backside numbingly uncomfortable seats that give you backache after 10 minutes, robotic announcements and lighting that looks like it comes from someone's garage? well, that's something to look forward to, isn't it?
Hopefully not! Although the 701s on order will be of a similar layout in terms of seating arrangement and walk through carriages, they are built by a different company so hopefully those issues will be resolved...