We have now stayed here several times when flying out of Heathrow, not just Terminal 5 where all you have to do is to walk across the covered walkway straight into the terminal but sometimes making use of the limo or cab transfer to other terminals for which there is a charge, rather than take the Underground.
The best thing about this hotel is not only the convenience of being able to park your car in safety in the car park right underneath the hotel while you are away for which there is an additional charge, being able to go down in the lift to your car parked exactly where it was when you left, but also the fact that this is a top class hotel.
When we stayed here recently we had the most delicious dinner in Vivre which is the cheaper of the two restuarants and then a fantastic buffet breakfast also in Vivre. In our case we went for the room option which included breakfast and two weeks parking. We paid for an up-grade to a deluxe room and asked for this to be one with outside windows as many of the rooms overlook the atrium and we prefer the outer ones. The standard of service in Vivre and elsewhere in the hotel is outstanding.
We also use the Sofitel at Gatwick but this one has the edge by quite a long way.