My wife and I stayed here for a couple of weeks and had an overall great experience. The place is located right in the Del Carmen area, literally three to five minutes walking distance to the cathedral and the market. There are several restaurants just outside and a supermarket two minutes away.
We stayed here in November so closing the windows was not a problem and the noise from the outside didn't bother us. But if you're looking for a quiet spot - be aware that this is a "center of the city" location with all the outside life (noise) that comes with it. Again, personally I loved it.
Inma was very lovely and met us to check us in which was very convenient. She was also great to communicate with - very responsive.
There were just two of us so we had plenty of space and could use the extra bedroom to store our suitcases. It's not a brand new place and the "luxury" word in the description probably isn't the best choice. But it is a really good apartment in a fantastic area if you want to explore Valencia without even needing to use any transportation.
One final note... I always depend on a fast Internet connect and this turned out to be a challenge. The place had older wiring and my internet speed was about 10 Mbps for download and only about 0.6 Mbps for uploads and the modem kept dropping the connection. Inma was very responsive and she initiated an upgrade with her Internet provider, but it didn't happen in time for our stay. For most people this probably won't be an issue, but if need fast connection, check with Inma that the updated connection is in place.