We stayed at the Renaissance Arc de Triomphe property in April on award stay. Upgraded to an architectural room (lower floor, overlooking main street) without prompting. Offered breakfast vouchers because there isn't a CL, several options for platinum arrival gift. (We opted for chocolates and water.) Staff was very friendly and bellmen worked hard to get cabs early in the morning.
Room was a good size with wall of windows, bathroom was pretty small and shower leaked everywhere, but the location was fantastic. The metro was two short blocks away. We walked down to the Eiffel Tower the first night - it was a beautiful walk. We passed the Trocadero property one day - I wouldn't mind trying that one next time, but it is not as close to the Metro as Arc de Triomphe. The area around the CE property was too frantic to me - it would be like staying in Times Square.
Overall, it was a solid stay with a fantastic location. We ended up extending our trip and the staff had no problem letting us keep our room and extending the reservation.