I have spent 5 nights in the BLC Design due to my busyness trip in Paris.
The location for me was strategic as I spent most of my time in the 11th, 12th and 13th districts.
However if you are in Paris for leisure I would still recommend the hotel as you can easily access the city center and more touristic areas with the Parisian metro or by bus.
My room was cleaned up on a daily basis based on the highest standards. It was very peaceful, perfect to rest after a busy day.
The stuff is very kind, very profession and always at your disposal, no matter what do you need.