Monica's place is very good, sanity is exellent, you have the air conditioner, a television with a lot of canals for when your bored and you are at proximity with a super-market, a litle foot park where you can play with the locals, a night club is around 25 minutes at feet (wich is great because the metro clause early in Valencia) and there is a mall (il cortès inglés) at proximity.
In addition to that the host is very cooperative and do your best to help you during your trip : for example, our wifi didn't worked at our arrival... it took only 1 day for a technician to come and help us fixe the problem.
The cash deposit of 200e is a bit unorthodox, but all is good, you can trust the host she gives back the money if everything is good at the end of the journey :)
Only problem : Like i said earlier, Valencia metro close early, and the beach is poorly desserved, so count at least 25-30 minute to go to the beach each day (a litle bit of determination and everything will be alright)