Stayed for two nights for work , having also recently stayed at the Pullman across the road.
While the stay was okay, the experience at the Pullman was greatly superior.
At the Pullman The rooms are newer and more spacious, while the breakfast was beautifully prepared and presented.
At the Mercure, the room ( level 1) was showing signs of age with a very tine bathroom and chipped furniture. Breakfast is served at the Club which was like being on a school camp with food presented from bay marees of questionable quality and age!
The staff are great at the Mercure and the gym was actually more spacious and had more options.
My choice????? If the price is similar then take the Pullman.