The Mercure Hyde Park hotel is definitely located in a great location, 5 min from Paddington which makes it extremely easy to commute from/to Heathrow (using Heathrow Express) and to travel to anywhere in London.
*If arriving from Paddington there's a shortcut to get into the Mercure Hyde Park from London St. via the Hotel Indigo, that way the walk will take you 3 min*
Besides the central location, the staff at the hotel was very kind and helpful, there's a cafe downstairs in the lobby so you can always grab a bite or have a cup of coffee.
The only downside was the room, it wasn't the room that was shown in the pictures, but it's an acceptable room for a couple that just needed a place to sleep, there were some issues with the shower not draining properly.