We stayed two nights (Sat - Mon), on a very good rate for bed and breakfast. The room was comfortable and of a good size, although getting ready for redecoration. The aircon was turned off in October, so the room was hot until we opened the window (ok as we were at the back, but would have been noisy in the rooms at the front of the hotel). The breakfast was also of good quality and plentiful.
The hotel is only five minutes walk from the historic centre, and with a tram stop outside the hotel if needed, so it's a good base for tourists.
We booked through hotels.com, and my gripe is with them, because their website stated that the hotel had a private car park (the hotel's own website states, correctly, that parking is in a public car park). We have quite an expensive car, so a secure car park was a key consideration when booking, and we were very concerned that we had to leave our car in an underground public car park about 300m from the hotel. Out parking cost EUR 25 two days in this car park, when hotels.com had said it would cost EUR 14 in the Mercure's own car park. The hotel was apologetic, but said the misrepresentation wasn't their fault.