I've stayed at the Cardiff twice while on business in London. The location can't be beat. You are 50 yards from Paddington Station, with access to the Heathrow Express and the fabulous London Underground. There are plenty of pubs and good restaurants in the neighborhood as well. On the downside, the rooms are very small, cold, and the wifi is sporadic. Breakfast is included...let's just say that it's good to have a Burger King and Starbucks nearby! Try to avoid the rooms on the upper floors, as this hotel does not have a lift. Definitely try to get a room with an en suite lavatory & shower, and preferably one facing the back of the building (the front side can be noisy at night). I'd stay here again if budget was a concern.

A small hotel near Paddington, in an area with many B&B.
My room was very cold, I asked them to move me and they did it, but also the second room they gave me was quite cold, they have an electric radiator in each room, they know it...
The room is small and the bathroom is ridicle, really too small, you don't know where to put your bath soap!
It was not dirty but in the average of this Uk B&B.
The breakfast choice is very limited if you do not order the Full English Breakfast.
Price is not bad, but I will not return there.

This place reminded me of some of the B&Bs I stayed in while in London during the seventies.
If it's luxury you're after, this place isn't for you .... the rooms are a touch old fashioned and very small (we had to close the bathroom door to get into bed) and the stairs to the 3rd floor are a bit of a trial.
BUT!!! if you're a tourist, wanting to see London, this is the place to stay. 2 minutes walk to Paddington station. The stop for the tour bus is just around the corner. Restaurants, cafes, medical centre, post office, bank, laundromat, Tescos etc etc, all within very easy walking distance. And Norfolk square is rather pretty and very quiet.
A good, hearty English breakfast was big enough to keep you going most of the day, and they came and asked if you wanted more; or there was a buffet style continental breakfast if that's your preference.
The staff were friendly and helpful. This place was very good value for money!!!

As per other reviews the rooms are small but for the price and location it is great value. You only need to sleep, have a hot shower and eat breakfast and it has all of that.