I used to stay there frequently on business - the HQ for my former employer's international division was based in the immediate neighborhood of Earl's Court.

The only real negative I had was the difficulty of catching a cab at times. Most of the taxis were going to/fro Heathrow on Cromwell Road, making it harder to get a cab than at some other locations (seeing as I was walking distance to the office, this was a minor inconvenience to me). There are a LOT of other lower-end tourist motels in the area.