I see there are a few negative reviews on here of the Royal Park, however I must say that I've been staying here regularly for the last couple of years and have found this to be an excellent hotel that suits my needs well. Most of the rooms are quiet and well appointed, the ventilation and a/c works well, and isn't too noisy, and I love that I can have breakfast delivered to my room allowing me to catch up on work emails etc before heading out.
Staff are always helpful and friendly, and internet access is (normally) fast and free of charge. They also have nice touches like tea or coffee on arrival and every evening from 19:00-20:00 complimentary champagne and canapés are served by the fire - marvellous !
I don't often eat here in the evening (only room service available for this) but when I have the food has been fine.
So, all in all a good hotel in central London that's only 5 minutes walk from Paddington Station and is friendly and relaxing.