Positive:
Fantastic location, minutes from Saint George's Metro & square. Easy walk to Opera & surrounding area. Villagey feel with wide range of cafes & places to eat, sweet little tree lined square right next to apartment popular with locals , good place for a drink & people watching. Spotless comfortable apartment with everything we needed, air-conditioned lobby downstairs with seated area, baggage storage available.. Easily accessible for Gare du Nord/ Eurostar. Saint George's area lots of character, beautiful buildings & when we were there the air around the metro was scented by the honeysuckle which was growing everywhere. Boulangeries & supermarkets nearby. Note, nearby is Pigalle which has a very different vibe & whose reputation precedes it..... we favoured staying down at the Saint George's end apart from a walk up to Montmartre.
Negative:
Nothing, might have preferred a cafetiere rather than a capsule coffee machine but this is personal choice & minor.