Koen is great host. The location of the apartment couldn't be better. Its just off Manneken Pis and the Grand Place, the two most frequented tourist attractions in Brussels.
The apartment is clean, modern and tastefully decorated. With all the expected amenities and more. The only downside is that Koen isn't available to let you in till after work (6pm). We took that opportunity to spend the day in Antwerp while waiting for him as our flight arrived at 930am.
Just below the apartment is Moeder Lambic. The food there is great and so is the atmosphere. There are a few good restaurants within short walking distance from there but outside the tourist trap area, which is great.
The best part I miss is laying on the couch with my headphones on, reading my book and glancing out the window of the apartment.
If you're in Brussels, this is the place to live.