Maria couldn't have been more welcoming to my husband and I if she tried. She was extremely responsive before and also during our stay. Maria came by to see us on our first morning in the apartment to give us local tips and suggestions and to also see if we had everything that we needed. Maria recommended that we go and see St Nichols - this should be on everyone's list!
It was also my birthday whilst we were in Valencia, so Maria kindly offered to recommend and book a restaurant for us. We went to La Pepica by the sea and the paella was incredible. Definitely go here for a meal during your stay - but make sure you ask Maria to book it for you, as there was just a sea of reserved table signs when we went for lunch on Thursday!
The apartment itself was extremely clean, well presented and in easy walking distance of the old town. If you turn left out of the apartment and walk for 5 minutes (max.) just passed the supermarket, you'll come to the ring road, on your left is the bus stop - jump on the 95 to take you straight down to the beach or the aquarium. It'll cost 1.5E each/each way and is really easy. This is also where you'd go to grab a cab - we waited less than 5 minutes. It cost approx. 20E including the tip to the airport. Maria is happy to arrange a cab for you, but we walked through so we didn't pay a call out charge.
If you're thinking of going to Valencia, then definitely stay with Maria.