Wow, what a wonderful apartment! It was perfectly clean (and, we are very picky about cleaning). It is large and well-equipped (we ate in a couple nights, and we had all the pots & pans, etc. that we needed.)
Slapen in Apen is in the perfect location. Very close to everything you will want to do and see, and yet very quiet. There is outdoor space for a morning coffee or a happy hour beer (with a view of the cathedral!)
Catherine was a great host - she met us to show us the apartment, and then spent the time to give us many tips on things to do and, most importantly, where to eat and drink! We really appreciated the local tips.
The stairs to the apartment are steep, so if you have mobility issues, this may not be the right place for you. But, otherwise, this is the PERFECT place to stay in Antwerp! We want to live here! :-)