First of all, the location is PERFECT. We only had a day in Brussels and we were able to see/explore plenty in that day!
The hosts were amazing with communication. I couldn't find the entrance to the apartment at first, and they were very quick to respond and very helpful.
The only thing to note is the staircase is a bit small and much different then stairs in the US. I wouldn't recommend it for anyone elderly or anyone who has mobility issues. That is the only "con" i can think of, and it wasn't that big of a deal to us.