This is a great place to stay overall. It is within walking distance from pretty much everything, and it is in a safe area. The only issues we experienced were the room not being ready when we checked in, so we had to leave and walk around for a couple of hours until the room was ready, and the cleaning crew tried to enter the room one morning while we were still there (they must have thought we checked out already).
It seems like the hiccups we had were isolated incidents, and I think that any couple looking for a great place to stay in Brussels would love this apartment. It is very secure and very clean.