LOCATION
Seriously awesome location – we basically didnt take the metro, which you’d need to if you stayed in an area like Montparnasse or lower parts of Latin Quarter. Walking distance to all (i mean ALL) the attractions (assuming you are spending whole days in a dedicated area, not darting about in a given day).
The price of dining is very high, but that is part-and-parcel of this location. There’s heaps of supermarkets around, so we cooked dinner cheaply every night.

THE APARTMENT
Clean and comfortable (if you’re not a princess about living conditions).
Great security – felt safe leaving valuables at home without a doubt.
Since Paris is so expensive for food, I imagine most people would be cooking. The kitchenette contains the BARE necessities, but it’s sufficient.
Dish washing liquid was on it’s last few millilitres and no replacement bottle, which was irritating. No soap in bathroom for handwashing. The Kettle is old, dirty and needs to be descaled, so boiling water for tea wasnt an option. Towels are provided but they’re very old and tatty, so we didnt use them. The curtain above the bed is very dusty so we slept with our heads the other side of bed. The mini-oven is also stick and not cleaned, so toasting things wasnt an option either.

We never met the owners, but they adequately answered questions we had. Otherwise, no real interaction or handholding.

Overall, great value for the price, so just pick this one. The negatives I listed are small and immaterial in the end. You want an awesome base to explore from and I put forth this one.