We were lucky enough to stay at Franz Y Cata's for four nights. They were easily contactable and communication was good.
The apartment building is clean and modern with very fast wifi which didn't drop out.
There are a few stains on the carpet/sofa but generally the apartment is clean.
The metro is a few blocks away, within walking distance, and the Plaza de Armas is very close. There is also a very good Indian restaurant (located in the Majestic Hotel) just a couple of blocks away.
Thanks for having us stay.