Marike and Wolfgang are great hosts: there was everything we needed at the flat and more (beer and soft drinks), all the stuff in the flat is fancy-ish and high quality. There's some nice outdoor space although we never used it. Whenever we had any problems, hosts were ready to help and quickly come by if needed.
A minor issue was that you can hear quite well what's happening in your neighbor's room and especially the sound of water turning on (boiler buzzes when heating up, I guess). So whenever our sleeping schedules didn't match (or there were some people in the night by the windows), we had to use earplugs.
Though I did have to pay over 300 pounds extra for the bedding + mattress protector + pillow I've damaged with stains (to be fair, I was able to receive most of the damaged bedding to keep), I don't think it should influence the rating much as it was a rather unusual situation and the stay was nice in general.