Last week I spent two nights at Ibis Opéra Hotel in a double non-smoking room on the 6th floor.
In my opinion, location is the best quality of this Ibis: this hotel, as a matter of fact, is conveniently located in the centre of the town, more precisely in Place De La Republique Française, which is the heart of Liege. As the name itself suggests, the Opera palace is a stone's throw from the Ibis and other important financial and administrative buildings are close to it. The location is extremely convenient also because, in front of the hotel's building, there are many bus stops, thanks to which many parts of the city can be easily reached.
Plus, next to the hotel, there are a lot of 'brasseries', restaurants and fast foods (e.g. a Quick restaurant, the Belgian fast-food chain, one Mac Donald's, which is next to the entrance of the hotel and a Pizza Hut in front of the building).
As regards the rooms, I can say that my room (number 610) was spacious and clean, with a nice view on the square and a nice bathroom with a wide and relaxing shower.
Finally, as far as the tariffs are concerned, I think that this hotel's rates are quite acceptable, if compared to the prices of the other hotels in town: I had booked the room in advance on booking.com and paid 67 euros (per night per room) plus 3 euros of taxes (per person, daily) for it. Generally speaking, this price may not be considered as extremely cheap but the location is worth it because this hotel is known by everyone in Liege and therefore it is a point of reference for tourists and local people.
The reception is always open and the receptionists are very polite and professional,
For all the reasons above, I strongly suggest a stay at this hotel.