Stayed here 4 times this year.
We choose it because it is a short walk to the terminal in the morning for the first BA flight to LHR. We tend to drive to the airport the night before the flight, drop off bags and I drive to the Long Stay car park (cheaper than an overnight at the hotel and the park and fly option is often more expensive than our option) and then walk back to the hotel, or take the shuttle bus back to the terminal if it's raining/snowing.
The bar and restaurant offer reasonable fare and the staff across the hotel are generally helpful.
On the occasion that we have taken breakfast at the hotel, the hot items have been OK for a Doubletree.
I have been staying here since the place opened (in c 2011/12 I think) and it does a very good job (for us !!) in my view.
In some of the rooms the plug sockets are a little temperamental and in need of repair/replacement but other than that the rooms are in good order.
Hope this helps.
Jetsetmonty