The Heathrow Express runs from London Paddington to London Heathrow airport. The journey is advertised as taking 15 minutes – although I’ve been on journeys that have taken up to 30 minutes. Fare is £25 peak or £22 off-peak. Their website has this little infographic:

What they don’t mention is the Heathrow Connect service. Journey time is 30 minutes. Fare is £10.30 – less than half the cost. The Heathrow Connect website doesn’t do much of a job selling the service and uses this tagline:
“When time is not an issue.”
Whereas they should say:
“Only 30 minutes to Heathrow for less than half the cost.”

I had been staying at the Hilton Paddington and so it was just a short walk from the rear exit of the hotel to the platforms and ticket office.

My Heathrow Connect train was empty:

I could see a full Heathrow Express on the adjacent line:

My train pulled into Heathrow Terminals 2 & 3 on the same platform as the Heathrow Express. If you need T4 or T5, you need to change to the Heathrow Express, but that is free.

So unless you’ve just missed a Heathrow Connect, or cost isn’t an issue, just ignore the Heathrow Express and make yourself comfortable on the Connect train.