I have stayed at the Mercure in the same properly so wanted to try the Ibis to see how different it was as ever it's a big difference in price between the two.
I was pleasantly surprised with the Ibis. The staff were great and efficient, I've of the fastest check in services i have ever had and the housekeeping team were excellent and very friendly.
Compared to the Mercure the rooms are smaller but actually the rooms seem cleaner and more vibrant.
I would definitely stay here again as a solo traveller but not as a couple of with a family due to the space issue but otherwise great choice