Requested to pay full amount upon arrival.
Request to keep passport as an additional guarantee
One evening, back from work, I found the door of my room opened. They just forgot to close it after cleaning (fortunately, nothing was missing in my room).
Some staff pay very few attention to the customer: enter in the room in the morning while you are sleeping without looking at the "Do not disturb" red indication hanging at the door's knob...
Low dedication to customer satisfaction, with regards to internet connection recurring problems, laundry pick up and delivery, airport pick up, restaurant orders...
Food choice is very limited, which is an inconvenient for long stay customers.

As a conclusion, I had a very bad experience in every field.
This hotel does not diserve its 4 stars.

Reserved minimum priced room,but was large, with good furnishings and bathroom. Very comfortable mattress and pillows. Room very quiet, even though we were on first floor on busy Al Maktoum Road. Swimming pool not glamourous, but has shady areas (essential in May temperatures) with gym, suana and massage facilities. Would stay again at bargain price of £90 per night .
Breakfast mediocre, but just across the road in Baniyas Road is a 5 star hotel of a famous chain that has wonderful breakfasts for 10 Dirhams more, and two amazing restaurants for dinner, one being the first Gordon Ramsay restaurant outside UK.
Small supermarket that seems to sell everything in same block as Hotel Dubai Concorde, and two bigger local supermarkets in road behind hotel. Hotel is walking distance to Deira City Shopping Centre, and the Creek.

this was $94 per night per person and gave us 4* accom within 3 minutes walking distance of Dubai creek. Unless you want the 7* treatment or you want self catering - Id say this was an excellent mid-range choice for dubai and allows you to spend more money in the souks or at the visitor attractions.

ps. if you have just won the lottery stay at the royal mirage