We are a family with two kids, 9 and 11, and spent a week here in August. Overall, we enjoyed our stay in the apartment. (This is only our second stay in an AirBnb apartment). First, the apartment was as advertised in terms of roominess, light, cleanliness and the various listed amenities. (The only disappointment might have been the small balcony, which appears more interesting in the photos than it was to us once we arrived. Besides, with the nightly rain, the chairs were always wet).
The location has the advantage of being close enough to the center as well as feeling quite local. Exploring the streets around leads to lots of interesting places to eat, as well as small playgrounds (on the side streets to Haarlemmerstraat) where our kids could play like neighborhood kids. The 12-15 minute talk to Centraal is easy, as well as getting to trams along Singelgracht.
We found the stairs to be manageable, although we only had carry-on suitcases. The street entrance doorknob requires a little careful handling, as it is quite close to the door jam (and trimmed on one side). The apartment is not over-furnished, so preserving a lot of openness, which I liked. Perhaps a little more decor would be more appealing. The beds were surprisingly comfortable for us. My wife and I took the rear-facing bedroom, which is a touch smaller but quieter. The toilets are on the upper floor of the apartment so, with kids, there is a lot of stair traffic inside the apartment. (Note that the floors are unvarnished wood). Two of the days were quite warm (we even got mosquito bites) with a lot of heat buildup on the top floor. The fan towers provided by Remco were perfect for the task of cooling it down.
We cooked a few meals and found the plates, silverware and glasses to be more than sufficient. The cutting knives and cookware were adequate for simple meals. (A grater would have been useful). If you are bringing small children and need to keep them occupied while you are busy, find out ahead of time whether the channels on the TV will meet your needs. It seemed to us that the TV only provided channels, so our kids ended up watching their Netflix and Youtube shows on our iPhones.
Remco was a welcoming host. He came to greet us after we'd already checked in, offered us local tips. When we were in need mid-week for a few replacement bulbs and a dustpan, we got them soon enough.