Paddington's main line isn't yet electrified, but I saw them putting up some poles and even stringing up some wire in some places, so it looks like it will soon enough. The Waterloo lines, though, are another story. Well, for an amusement park-type ride, I guess. This is, as you may have guessed, stupid. Trains run quite often, and I found that the drivers can be fairly friendly and helpful.
Trains can be pretty fast, but as they get faster, they get really noisy.