Ellen's place is a great option if you're staying in Amsterdam for a few days.
pros: spotless clean, very comfortable bed and couch, extremely well equipped (cutlery, plates, coffe machine, kettle, towels, shampoo, etc). The room is kind of separated from the rest of the house so you do not feel like you are intruding in someone's home. Ellen is a good hist and is very communicative and polite.
Cons: the only con is that the location is a bit inconvenient, or to be precise - the public transport is. Comming back to the room in the evening can mean waiting times of up to 30 mins for the bus. If you are visiting in Spring or Summer you can always take the public transport bus which is about 15 mins walk from the place, but in winter you'd want to take the "paid" transport (2mins walking), means you would have to spend a bit extra on transportation tickets.
Overall the place is great, the hosts are great, I would recommend this place for anyone who doesn't have mobility issues.