I know that this has been asked before, but the answers are quite old. Next Tuesday I arrive at Heathrow airport terminal 5 around 12:30 noon. I have purchased a "peak off return" ticket to Cambridge which I need to collect at a machine. It recommends taking the Express line to Paddington and then the tube to King's cross. At the same time, there is a warning that the tube might be crowded and delayed. Now I realized that there is a direct (but slower connection) via Piccadilly line. What do you prefer? Is my ticket valid for this alternative? I've never been to London.
EDIT after the journey: I wasn't able to enter Piccadilly line with my peak off return ticket (doors didn't open). I had to take the Express line to Paddington, but it was super easy to find and probably much faster anyway.
