Can't believe how many people say they love it. They clearly aren't frequent users of the tube in peak hours for normally people going and coming back from work (which is when most people use the tube).
It's incredibly crowded, you often can't get a seat. The general cleanliness of the floors is poor, and people are shoving and pushing so to cram everyone on the tube. You cling on to one of those holder things in the air, or a pole somewhere, hoping you don't fall down.
It's not a "pleasant experience" at all.
It may be quicker getting around London via the tube, which is why so many take it, but it's not an "enjoyable experience". If I could walk or even the bus took a similar amount of time I'd take that. But it doesn't.