The Tube is frankly amazing. I've used it virtually every time I've been to London, and it has never been much of a problem for me. Apart from some overcrowding on the platforms during rush hour, but that's to be expected.
With regard to today's earlier incident, this
is what apparently caused the problems on the Bakerloo line. There is quite a bit of a bulge in the tunnel, which apparently caused the obstruction that people thought was a tunnel collapse. Hopefully, it won't take too long to fix, but service is still suspended between Piccadilly Circus and Elephant & Castle.
Its future looks good, too, with the upgrade plans seemingly progressing well, and the brilliant new S Stock on the Metropolitan line. It's truly a great feat of engineering - even if most of the Tube network isn't actually underground.