Khao's place is in a very safe neighborhood with mostly locals. The apartment is a studio type apartment in an older building on the ground floor. The building is long term residents. Sound does carry, so if you sleep light, you will hear the tenants coming in or leaving for work. We didn't mind because we were in the city all day and slept hard due to sightseeing and walking everywhere. His apartment is in a perfect location for general needs. The grocery store and a laundry are across the street with cafes, bars, and bakeries just a block or two down in every direction. We loved the location because it wasn't in a high traffic area. We were all female and felt very safe walking through at any time of night. The bed was VERY comfortable as well.
American tips: buy a train pass to all zones the first day you arrive for all the days you are there. a three day unlimited pass was $55 Euros. Don't wait in line at the airport as you can purchase these at many stations. Also, when you leave the train station for the apartment, walk straight down the steps that are across from the exit. Then you can use maps to get to the apartment.
Bring the brands you can't live without, as some products simply don't exist in Paris. Also, if you have the room in your luggage, a towel/linens. There are some in the apartment, but items dry slow there.
Be prepared for smaller spaces such as restrooms. Plan ahead for restrooms as you will have to buy something (even at McDonalds) and there are always lines.
Uber is readily available and is the best way to get back to the airport. We took a train when we arrived, but shopped a lot and didn't want to carry an extra bag each. The Uber fare from the apartment to CDG airport is about $45 euros.
Do not wait till the last minute to eat if you want a true dinner. There is no hurry when going out to eat so if you are rushed, just go to a local cafe and grab a pastry or ham and cheese sandwich. There were no bad restaurants, they are very relaxed in service. They don't hover, so you will need to call someone over if you need attention. American style coffee is a pain to get, but there are lots of Starbucks throughout the city. Sugar free syrups at Starbucks are hit and miss.
We would absolutely book this again, as it was a perfect fit for our budget and needs. If you need a 5 star high dollar luxury room, this is not for you. If you want safe, comfortable, and budget friendly then this is it.