Martha's place is spotless and spacious and was located very conveniently for our worktrip. Two bathrooms are a bonus if you're three and trying to get out the house relatively swiftly. We didn't get to make use of the cute little terrace but it gave the flat extra light. It's right next to a great burger place and close to walk wherever we needed to go.
Overall I'd recommend this place to anyone wanting to stay in Vienna.