We stayed here twice in October, on our train travels round France. The first time they messed up our booking and gave our "superior" room to someone else(!), leaving us with a smaller "standard" room. They offered us free entry to the Banksy museum as an apology but we didn't have time to do it, so a bit of a disappointment there. The bathroom also had a bad smell that first time. BUT the beds were comfortable, the Banksy theme was fun, the prices weren't too bad, the location was really handy for Gare du Nord, the staff were friendly and the ethos of the place seemed good.
Our second visit was much better - they hadn't given our room away this time(!) and the bad bathroom smell was gone. Also, we had been a bit freaked out by the massive media hype about bedbugs in Paris, so were relieved to find this place was completely bedbug-free :) Which is probably true for most Paris hotels (the whole thing seems to be exaggerated really) but was still very much appreciated by us on this occasion...!