We stayed 6 nights in the apartment and enjoyed our stay. As others mentioned before there is a church in fron of the building and the bell is quite loud. One day it was ringing for 20 min at 7 am.
The apartment itself is huge and the check-in is really easy. You can find anything one needs in the flat. As others pointed out there are two big beds, but we wouldn't recommend it for 2 couples. We think it is more useful for a family. You don't have courtains for dividing the beds and it is loft style.
One night we were unlucky and it was raining so heavy that the water was leaking from the ceiling. We contacted the host agency but felt let alone with the problem. The first response of showing them pictures of the leaking was we should use the mop instead the towels. After it rained even more they told us they will someone next day. We spent the whole night capturing water from the ceiling. As there is not much rain in Valencia the buldings can't handle a lot of water. In the end we got at least a refund for this night and new towels.
Also there seems to be water under the tiles in the bathroom which is causing an unpleasant smell.
We stayed in the apartment anyway and the rest of our stay was ok.
The rooftop is big, but the view is partially blocked by other buildings.
We would probably not come again.