We just left London using the Just Airports car service to Heathrow. The driver was not only on time,
he was early and it was 5:00 AM. The car was immaculate, the driver spoke English and very courteous. I booked the car online for 38 lbs and ordered the middle size car. We had lots of room.
We had two people, two checked bags and hand bags. This was a great experience because our Uber service from our home city got lost and cancelled our pick up , which was a bad experience.
We did tip him, the service was great and much less of a hassle going via the train so early with all the steps.