This was possible the nicest flat I've ever stayed in! The flat is beautiful, and very clean. The shower is fantastic, with a huge shower head. The beds are incredibly comfortable, I didn't want to get up. Fortunately the flat is right in the middle of the old town (the tourist board Unesco walk includes walking up this street!), with a shop for breakfast pastries directly opposite and overlooking a fantastic old sqaure.
Crystel was very lovely. She answered all my email questions in English, despite saying she didn't speak English. Her eating recommendations were spot on (though you need to book some of the restaurants). In short this was a great flat, with a great host and I highly recommend it.