Hotel Celeste is a comfortable and extremely clean hotel in a fairly good location (25-30 min walk to the most popular tourist attractions)... Staff are extremely welcoming, friendly and helpful. Bed linen great quality and the bed was like sleeping on a cloud!
The only negatives from our perspective were things that we were already prepared for having read other guests reviews. We do agree that for the price you pay (not particularly high for Paris but compared to other city break destinations it is much more) one would expect additional cosmetic items (I forgot to take conditioner so this would have been helpful if provided, for instance). Similarly there were only herbal tea bags provided - no regular tea or coffee or milk, which meant we were absolutely gasping for a drink by the time we were up, ready and on the street searching for a suitable cafe. Finally the air conditioning worked perfectly on the first evening but we then seemed to have no ability to use the control panel (it all lit up and numbers/icons changed etc but it didn't actually do anything). Not a big deal for us and not worth us mentioning to the hotel but if it had been any warmer we would have been uncomfortable.
Strangely one of Hotel Celeste's strengths was also verging on a weakness. It was particularly quiet and restful (great for not being disturbed at night time) but this did lead to a bit of a lack of ambience/character. We rarely saw other guests even at reception, let alone anybody enjoying the chic interior downstairs (which was eerily silent at times!) or the small bar area.
Over all - great little hotel with great staff and high standards of cleanliness, however for the money paid and the impression we got from the Airbnb photographs I think we were expecting just a touch more luxury.